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Levant B, Villwock JA, Manzardo AM. Impostorism in American medical students during early clinical training: gender differences and intercorrelating factors. Int J Med Educ 2020; 11:90-96. [PMID: 32356519 PMCID: PMC7246127 DOI: 10.5116/ijme.5e99.7aa2] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 04/17/2020] [Indexed: 05/12/2023]
Abstract
OBJECTIVES This study examined the incidence and severity of impostorism in third-year medical students as they transitioned from the preclinical to clinical phases of training. METHODS A cross-sectional study was conducted in third-year medical students (N=215). Respondents completed a voluntary, anonymous, 60-item survey that included the Clance Impostor Phenomenon Scale and the Perceived Stress Scale. Student's-t, Mann-Whitney, and Chi-Square tests and Pearson correlation were used to determine differences between subgroups of students and relationships between instruments scores and demographic parameters. RESULTS Fifty-nine percent of students responded with N=112 (59% female) completing at least one instrument. The mean impostor score was 63.0 ± 14.6 (moderate-to-frequent impostor feelings) and was 9% higher in females (U=1181, p = .046). Perceived Stress scores for females were 17% higher than males (t(109)=2.87, p=.005). Females had lower United States Medical Licensing Examination (USMLE) Step 1 scores (t(107)= 3.06, p=.003). Impostor and perceived stress scores were correlated for males (r(46)=.47, p=.002) and females (r(64)=.54,p<.0001). Impostor and USMLE Step 1 scores were negatively correlated for males (r(45) =-.32, p= .034) but not females (r(63) = -.11, p=.40). CONCLUSIONS These findings demonstrate the intercorrelation between impostorism and stress in male and female medical students and raise interesting questions regarding the contributions of gender and other factors involved with medical training.
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Affiliation(s)
- Beth Levant
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS, USA
| | - Jennifer A. Villwock
- Department of Otolaryngology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Ann M. Manzardo
- Department of Psychiatry and Behavioral Sciences, University of Kansas Medical Center, Kansas City, KS, USA
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Abstract
INTRODUCTION Impostorism, feelings of distrust in one's abilities and accomplishments despite evidence to the contrary, is frequent in medical students and negatively affects student wellness. METHODS The aspects of impostorism that were most prevalent in medical students during the transition from the preclinical to clinical phases of their training were assessed using an anonymous, voluntary 60-item survey that included the Clance Impostor Phenomenon Scale (CIPS) and a 2-item burnout assessment administered in October-November 2018. Ratings of individual CIPS items were compared between items for the entire sample and in subpopulations of students. The correlation of individual CIPS items with CIPS total score was also determined. RESULTS A total of 127 of 215 (59%) surveyed students responded, with 112 completing the CIPS with mean score of 63.0 ± 14.6 (moderate-to-frequent impostor feelings). Ratings of individual CIPS items differed significantly between items. Responses also differed depending on gender and perceived burnout or depersonalization. DISCUSSION Third-year medical students identified most strongly with items related to unfounded fear of failure, hesitance to share recognition before it is announced, remembering failures rather than successes, believing themselves less capable than others, and worrying about succeeding. In contrast, attribution of accomplishments to luck was not prominent for these students. Responses to certain items also differed depending on gender and perceived burnout or depersonalization, but not self-reported under-represented minority status. This observation may inform the development of interventions tailored to foster wellness as students negotiate the transition from the preclinical to clinical phases of their training.
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Affiliation(s)
- Beth Levant
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS, USA.
| | - Jennifer A Villwock
- Department of Otolaryngology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Ann M Manzardo
- Department of Psychiatry and Behavioral Sciences, University of Kansas Medical Center, Kansas City, KS, USA
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Orrù M, Strathman HJ, Floris G, Scheggi S, Levant B, Bortolato M. The adverse effects of pramipexole on probability discounting are not reversed by acute D 2 or D 3 receptor antagonism. Eur Neuropsychopharmacol 2020; 32:104-119. [PMID: 31983530 PMCID: PMC9325630 DOI: 10.1016/j.euroneuro.2020.01.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 12/06/2019] [Accepted: 01/07/2020] [Indexed: 02/08/2023]
Abstract
Pramipexole (PPX) is a D2 and D3 dopamine receptor agonist approved for clinical use, which is associated with a higher risk of impulse-control disorders. Using a rat model, we recently found that low doses of the monoamine-depleting agent reserpine (RES; 1 mg/kg/day, SC) dramatically increased the untoward effects of PPX (0.3 mg/kg/day, SC) on probability discounting, a key impulsivity function. To further understand the neurobehavioral mechanisms underlying these effects, we first tested whether the combination of PPX and RES may lead to a generalized enhancement in risk taking, as tested in the suspended wire-beam paradigm. The association of RES and PPX did not augment the proclivity of rats to cross the bridge in order to obtain a reward, suggesting that the effects of RES and PPX on probability discounting do not reflect a generalized increase in impulsivity. We then studied what receptors mediate the effects of PPX in RES-treated rats. The combination of RES and PPX increased membrane expression and binding of D3, but not D2 dopamine receptors, in the nucleus accumbens. However, the behavioral effects of PPX and RES were not reduced by acute treatments with the D2/D3 receptor antagonist raclopride (0.01-0.05 mg/kg, SC), the highly selective D2 receptor antagonist L-741,626 (0.1-1 mg/kg, SC) or the D3 receptor antagonists GR 103691 (0.1-0.3 mg/kg, SC) and SB 277011A (1-10 mg/kg, SC). These findings collectively suggest that the effects of PPX in probability discounting do not reflect generalized enhancements in impulsivity or acute dopamine D2 or D3 receptor activation.
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Affiliation(s)
- Marco Orrù
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Skaggs Hall, Room 3916, 30 S 2000 E, Salt Lake City, UT, Unites States
| | - Hunter J Strathman
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Skaggs Hall, Room 3916, 30 S 2000 E, Salt Lake City, UT, Unites States
| | - Gabriele Floris
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Skaggs Hall, Room 3916, 30 S 2000 E, Salt Lake City, UT, Unites States
| | - Simona Scheggi
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Skaggs Hall, Room 3916, 30 S 2000 E, Salt Lake City, UT, Unites States; Department of Molecular and Developmental Medicine, School of Medicine, University of Siena, Italy
| | - Beth Levant
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS, Unites States
| | - Marco Bortolato
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Skaggs Hall, Room 3916, 30 S 2000 E, Salt Lake City, UT, Unites States.
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Levant B, Zückert W, Paolo A. Post-exam feedback with question rationales improves re-test performance of medical students on a multiple-choice exam. Adv Health Sci Educ Theory Pract 2018; 23:995-1003. [PMID: 30043313 DOI: 10.1007/s10459-018-9844-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 07/18/2018] [Indexed: 06/08/2023]
Abstract
This study compared the effects of two types of delayed feedback (correct response or correct response + rationale) provided to students by a computer-based testing system following an exam. The preclinical medical curriculum at the University of Kansas Medical Center uses a two-exam system for summative assessments in which students test, revisit material, and then re-test (same content, different questions), with the higher score used to determine the students' grades. Using a quasi-experimental design and data collected during the normal course of instruction, test and re-test scores from midterm multiple choice examinations were compared between academic year (AY) 2015-2016, which provided delayed feedback with the correct answer only, and AY 2016-2017, where delayed feedback consisted of the correct answer plus a rationale. The average increase in score on the re-test was 2.29 ± 6.83% (n = 192) with correct answer only and 3.92 ± 7.12% (n = 197) with rationales (p < 0.05). The effect of the rationales was not different in students of differing academic abilities based on entering composite MCAT scores or Year 1 GPA. Thus, delayed feedback with exam question rationales resulted in a greater increase in exam score between the test and re-test than feedback with correct response only. This finding suggests that delayed elaborative feedback on a summative exam produced a small, but significant, improvement in learning, in medical students.
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Affiliation(s)
- Beth Levant
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS, 66160, USA.
| | - Wolfram Zückert
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Anthony Paolo
- Office of Medical Education, University of Kansas Medical Center, Kansas City, KS, 66160, USA
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Kaplan SV, Limbocker RA, Levant B, Johnson MA. Regional differences in dopamine release in the R6/2 mouse caudate putamen. ELECTROANAL 2018; 30:1066-1072. [PMID: 29955208 PMCID: PMC6016844 DOI: 10.1002/elan.201700827] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 03/09/2018] [Indexed: 01/23/2023]
Abstract
Huntington's disease (HD) is a fatal neurodegenerative disorder that is characterized by degeneration of the striatum. Here, fast-scan cyclic voltammetry at carbon-fiber microelectrodes was used to uncover regional differences in dopamine (DA) release in the caudate putamen of R6/2 and wild-type control mice. We found a decreasing ventral-to-dorsal gradient in DA release, evoked by a single electrical stimulus pulse, in aged R6/2 mice. Moreover, under more intense stimulation conditions (120 pulses), DA release was significantly attenuated in the dorsal, but not in the ventral caudate. Autoradiography measurements using [3H]WIN 35,428 revealed that the overall density of DA transporter (DAT) protein molecules was significantly less in R6/2 mice compared to WT control mice; however, quadrants of the caudate putamen were not differentially altered in the R6/2 mice. These data collectively suggest that DA release in the dorsal caudate region is more vulnerable with age progression compared to the ventral region.
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Affiliation(s)
- Sam V. Kaplan
- Department of Chemistry and R. N. Adams Institute for Bioanalytical Chemistry, University of Kansas, Lawrence, Kansas 66045 USA
| | - Ryan A. Limbocker
- Department of Chemistry and R. N. Adams Institute for Bioanalytical Chemistry, University of Kansas, Lawrence, Kansas 66045 USA
| | - Beth Levant
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160 USA
| | - Michael A. Johnson
- Department of Chemistry and R. N. Adams Institute for Bioanalytical Chemistry, University of Kansas, Lawrence, Kansas 66045 USA
- Neuroscience Program, University of Kansas, Lawrence, Kansas 66045 USA
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Healy-Stoffel M, Levant B. N-3 (Omega-3) Fatty Acids: Effects on Brain Dopamine Systems and Potential Role in the Etiology and Treatment of Neuropsychiatric Disorders. CNS Neurol Disord Drug Targets 2018; 17:216-232. [PMID: 29651972 PMCID: PMC6563911 DOI: 10.2174/1871527317666180412153612] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 11/01/2017] [Accepted: 02/08/2018] [Indexed: 02/06/2023]
Abstract
BACKGROUND & OBJECTIVE A number of neuropsychiatric disorders, including Parkinson's disease, schizophrenia, attention deficit hyperactivity disorder, and, to some extent, depression, involve dysregulation of the brain dopamine systems. The etiology of these diseases is multifactorial, involving genetic and environmental factors. Evidence suggests that inadequate levels of n-3 (omega- 3) polyunsaturated fatty acids (PUFA) in the brain may represent a risk factor for these disorders. These fatty acids, which are derived from the diet, are a major component of neuronal membranes and are of particular importance in brain development and function. Low levels of n-3 PUFAs in the brain affect the brain dopamine systems and, when combined with appropriate genetic and other factors, increase the risk of developing these disorders and/or the severity of the disease. This article reviews the neurobiology of n-3 PUFAs and their effects on dopaminergic function. CONCLUSION Clinical studies supporting their role in the etiologies of diseases involving the brain dopamine systems and the potential of n-3 PUFAs in the treatment of these disorders are discussed.
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Affiliation(s)
| | - Beth Levant
- Department of Pharmacology, Toxicology, and Therapeutics and the Kansas Intellectual and Developmental Disabilities Research Center, University of Kansas Medical Center, Kansas City, KS, USA
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Pes R, Godar SC, Fox AT, Burgeno LM, Strathman HJ, Jarmolowicz DP, Devoto P, Levant B, Phillips PE, Fowler SC, Bortolato M. Pramipexole enhances disadvantageous decision-making: Lack of relation to changes in phasic dopamine release. Neuropharmacology 2016; 114:77-87. [PMID: 27889491 DOI: 10.1016/j.neuropharm.2016.11.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 11/15/2016] [Accepted: 11/21/2016] [Indexed: 10/20/2022]
Abstract
Pramipexole (PPX) is a high-affinity D2-like dopamine receptor agonist, used in the treatment of Parkinson's disease (PD) and restless leg syndrome. Recent evidence indicates that PPX increases the risk of problem gambling and impulse-control disorders in vulnerable patients. Although the molecular bases of these complications remain unclear, several authors have theorized that PPX may increase risk propensity by activating presynaptic dopamine receptors in the mesolimbic system, resulting in the reduction of dopamine release in the nucleus accumbens (NAcc). To test this possibility, we subjected rats to a probability-discounting task specifically designed to capture the response to disadvantageous options. PPX enhanced disadvantageous decision-making at a dose (0.3 mg/kg/day, SC) that reduced phasic dopamine release in the NAcc. To test whether these modifications in dopamine efflux were responsible for the observed neuroeconomic deficits, PPX was administered in combination with the monoamine-depleting agent reserpine (RES), at a low dose (1 mg/kg/day, SC) that did not affect baseline locomotor and operant responses. Contrary to our predictions, RES surprisingly exacerbated the effects of PPX on disadvantageous decision-making, even though it failed to augment PPX-induced decreases in phasic dopamine release. These results collectively suggest that PPX impairs the discounting of probabilistic losses and that the enhancement in risk-taking behaviors secondary to this drug may be dissociated from dynamic changes in mesolimbic dopamine release.
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Affiliation(s)
- Romina Pes
- Dept. of Pharmacology and Toxicology, University of Kansas, Lawrence, KS, United States; Dept. of Biomedical Sciences, Neuroscience Division, University of Cagliari, Italy
| | - Sean C Godar
- Dept. of Pharmacology and Toxicology, University of Kansas, Lawrence, KS, United States; Dept. of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, UT, United States
| | - Andrew T Fox
- Dept. of Pharmacology and Toxicology, University of Kansas, Lawrence, KS, United States
| | - Lauren M Burgeno
- Dept. of Pharmacology, University of Washington, Seattle, WA, United States
| | - Hunter J Strathman
- Dept. of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, UT, United States
| | - David P Jarmolowicz
- Problem Gambling Research Studies (ProGResS) Network, University of Kansas, Lawrence, KS, United States; Dept. of Applied Behavioral Science, University of Kansas, Lawrence, KS, United States
| | - Paola Devoto
- Dept. of Biomedical Sciences, Neuroscience Division, University of Cagliari, Italy
| | - Beth Levant
- Dept. of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS, United States
| | - Paul E Phillips
- Dept. of Pharmacology, University of Washington, Seattle, WA, United States; Dept. of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, United States
| | - Stephen C Fowler
- Dept. of Pharmacology and Toxicology, University of Kansas, Lawrence, KS, United States
| | - Marco Bortolato
- Dept. of Pharmacology and Toxicology, University of Kansas, Lawrence, KS, United States; Problem Gambling Research Studies (ProGResS) Network, University of Kansas, Lawrence, KS, United States; Dept. of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, UT, United States.
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8
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Chen J, Jiang C, Levant B, Li X, Zhao T, Wen B, Luo R, Sun D, Wang S. Pramipexole derivatives as potent and selective dopamine D(3) receptor agonists with improved human microsomal stability. ChemMedChem 2014; 9:2653-60. [PMID: 25338762 DOI: 10.1002/cmdc.201402398] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Indexed: 12/21/2022]
Abstract
Herein we report the synthesis and evaluation of a series of new pramipexole derivatives as highly potent and selective agonists of the dopamine-3 (D3 ) receptor. A number of these new compounds bind to the D3 receptor with sub-nanomolar affinity and show excellent selectivity (>10,000) for the D3 receptor over the D1 and D2 receptors. For example, compound 23 (N-(cis-3-(2-(((S)-2-amino-4,5,6,7-tetrahydrobenzo[d]thiazol-6-yl)(propyl)amino)ethyl)-3-hydroxycyclobutyl)-3-(5-methyl-1,2,4-oxadiazol-3-yl)benzamide) binds to the D3 receptor with a Ki value of 0.53 nM and shows a selectivity of >20,000 over the D2 and D1 receptors in the binding assays using a rat brain preparation. It has excellent stability in human liver microsomes. Moreover, in vitro functional assays showed it to be a full agonist for the human D3 receptor.
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Affiliation(s)
- Jianyong Chen
- Departments of Internal Medicine, Pharmacology, and Medicinal Chemistry, University of Michigan, 1500 East Medical Center Drive, Ann Arbor, MI 48109 (USA).
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Chen J, Levant B, Jiang C, Keck TM, Newman AH, Wang S. Tranylcypromine substituted cis-hydroxycyclobutylnaphthamides as potent and selective dopamine D₃ receptor antagonists. J Med Chem 2014; 57:4962-8. [PMID: 24848155 PMCID: PMC4216217 DOI: 10.1021/jm401798r] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
![]()
We
report a class of potent and selective dopamine D3 receptor
antagonists based upon tranylcypromine. Although tranylcypromine
has a low affinity for the rat D3 receptor (Ki = 12.8 μM), our efforts have yielded (1R,2S)-11 (CJ-1882), which
has Ki values of 2.7 and 2.8 nM at the
rat and human dopamine D3 receptors, respectively, and
displays respective selectivities of >10000-fold and 223-fold over
the rat and human D2 receptors. Evaluation in a β-arrestin
functional assay showed that (1R,2S)-11 is a potent and competitive antagonist at the human
D3 receptor.
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Affiliation(s)
- Jianyong Chen
- Departments of Internal Medicine, Pharmacology, and Medicinal Chemistry, University of Michigan , Ann Arbor, Michigan 48109, United States
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Russell KL, Berman NEJ, Gregg PRA, Levant B. Fish oil improves motor function, limits blood-brain barrier disruption, and reduces Mmp9 gene expression in a rat model of juvenile traumatic brain injury. Prostaglandins Leukot Essent Fatty Acids 2014; 90:5-11. [PMID: 24342130 PMCID: PMC3906920 DOI: 10.1016/j.plefa.2013.11.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 11/14/2013] [Accepted: 11/21/2013] [Indexed: 12/15/2022]
Abstract
The effects of an oral fish oil treatment regimen on sensorimotor, blood-brain barrier, and biochemical outcomes of traumatic brain injury (TBI) were investigated in a juvenile rat model. Seventeen-day old Long-Evans rats were given a 15mL/kg fish oil (2.01g/kg EPA, 1.34g/kg DHA) or soybean oil dose via oral gavage 30min prior to being subjected to a controlled cortical impact injury or sham surgery, followed by daily doses for seven days. Fish oil treatment resulted in less severe hindlimb deficits after TBI as assessed with the beam walk test, decreased cerebral IgG infiltration, and decreased TBI-induced expression of the Mmp9 gene one day after injury. These results indicate that fish oil improved functional outcome after TBI resulting, at least in part from decreased disruption of the blood-brain barrier through a mechanism that includes attenuation of TBI-induced expression of Mmp9.
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Affiliation(s)
- K L Russell
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 USA.
| | - N E J Berman
- Department of Anatomy & Cell Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA.
| | - P R A Gregg
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 USA.
| | - B Levant
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 USA.
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Russell KL, Berman NEJ, Levant B. Low brain DHA content worsens sensorimotor outcomes after TBI and decreases TBI-induced Timp1 expression in juvenile rats. Prostaglandins Leukot Essent Fatty Acids 2013; 89:97-105. [PMID: 23796971 PMCID: PMC3753049 DOI: 10.1016/j.plefa.2013.05.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Revised: 05/22/2013] [Accepted: 05/23/2013] [Indexed: 12/31/2022]
Abstract
The effects of dietary modulation of brain DHA content on outcomes after TBI were examined in a juvenile rat model. Long-Evans rats with normal or diet-induced decreases in brain DHA were subjected to a controlled cortical impact or sham surgery on postnatal day 17. Rats with the greatest decreases in brain DHA had the poorest sensorimotor outcomes after TBI. Ccl2, Gfap, and Mmp 9 mRNA levels, and MMP-2 and -9 enzymatic activities were increased after TBI regardless of brain DHA level. Lesion volume was not affected by brain DHA level. In contrast, TBI-induced Timp1 expression was lower in rats on the Deficient diet and correlated with brain DHA level. These data suggest that decreased brain DHA content contributes to poorer sensorimotor outcomes after TBI through a mechanism involving modulation of Timp1 expression.
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Affiliation(s)
- Kristin L. Russell
- Department of Pharmacology, Toxicology, and Therapeutics, 3901 Rainbow Blvd., University of Kansas Medical Center, Kansas City, KS 66160 USA
| | - Nancy E. J. Berman
- Department of Anatomy & Cell Biology, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160 USA
| | - Beth Levant
- Department of Pharmacology, Toxicology, and Therapeutics, 3901 Rainbow Blvd., University of Kansas Medical Center, Kansas City, KS 66160 USA
- Corresponding author: Department of Pharmacology, University of Kansas Medical Center, Mail Stop 1018, 3901 Rainbow Blvd., Kansas City, KS 66160, Phone: 1 913 588 7527, Fax: 1 913 588 7501,
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Levant B, Ozias MK, Guilford BL, Wright DE. Streptozotocin-induced diabetes partially attenuates the effects of a high-fat diet on liver and brain fatty acid composition in mice. Lipids 2013; 48:939-48. [PMID: 23893338 DOI: 10.1007/s11745-013-3817-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Accepted: 07/12/2013] [Indexed: 02/08/2023]
Abstract
The current study addresses the effects of a high-fat diet on liver and brain fatty acid compositions and the interaction of that diet with diabetes in a type 1 mouse model. Adult, male, normal and streptozotocin-induced diabetic C57BL/6 mice were fed standard (14 % kcal from fat) or high-fat (54 % kcal from fat, hydrogenated vegetable shortening and corn oil) diets for 8 weeks. Liver and whole brain total phospholipid fatty acid compositions were then determined by TLC/GC. In the liver of non-diabetic mice, the high-fat diet increased the percentages of 18:1n-9, 20:4n-6, and 22:5n-6 and decreased 18:2n-6 and 22:6n-3. Diabetes increased 16:0 in liver, and decreased 18:1n-7 and 20:4n-6. The effects of the high-fat diet on liver phospholipids in diabetic mice were similar to those in non-diabetic mice, or were of smaller magnitude. In the brain, the high-fat diet increased 18:0 and 20:4n-6 of non-diabetic, but not diabetic mice. Brain 22:5n-6 acid was increased by the high-fat diet in both non-diabetic and diabetic mice, but this increase was smaller in diabetic mice. Diabetes alone did not alter the percentage of any individual fatty acid in brain. This indicates that the effects of a high-fat diet on liver and brain phospholipid fatty acid compositions are partially attenuated by concomitant hyperglycemia with hypoinsulinemia.
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Affiliation(s)
- Beth Levant
- Departments of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Mail Stop 1018, 3901 Rainbow Blvd., Kansas City, KS 66160, USA.
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Levant B. N-3 (omega-3) polyunsaturated Fatty acids in the pathophysiology and treatment of depression: pre-clinical evidence. CNS Neurol Disord Drug Targets 2013; 12:450-9. [PMID: 23574159 PMCID: PMC4115447 DOI: 10.2174/1871527311312040003] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Revised: 03/19/2013] [Accepted: 03/22/2013] [Indexed: 11/22/2022]
Abstract
A growing literature suggests the association of low tissue levels and/or dietary intake of n-polyunsaturated fatty acids (PUFA) with depressive illnesses. Animal studies show that low tissue and/or dietary n-3 PUFAs can lead to behaviors and neurobiological effects associated with depression and can potentiate the consequences of stress, whereas higher levels have the opposite effect. These data support the involvement of n-3 PUFAs levels in the disease processes underlying depression. In addition, these pre-clinical findings indicate neurobiological mechanisms whereby n-3 PUFAs may contribute to the disease including control of serotonergic and dopaminergic function, modulation of brain-derived neurotrophic factor (BDNF) in the hippocampus, regulation of the hypothalamic-pituitary-adrenal axis, and effects on neuroinflammation. This evidence for a role for n-3 PUFA in the pathophysiology and treatment of depressive illness are reviewed. The implications of these finding for future pre-clinical research and clinical application are discussed.
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Affiliation(s)
- Beth Levant
- Department of Pharmacology, University of Kansas Medical Center, MS-1018, 3901 Rainbow Blvd., Kansas City, KS 66160, USA.
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Healy-Stoffel M, Ahmad SO, Stanford JA, Levant B. Altered nucleolar morphology in substantia nigra dopamine neurons following 6-hydroxydopamine lesion in rats. Neurosci Lett 2013; 546:26-30. [PMID: 23643997 DOI: 10.1016/j.neulet.2013.04.033] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Revised: 03/30/2013] [Accepted: 04/24/2013] [Indexed: 01/06/2023]
Abstract
The nucleolus, the site of ribosomal ribonucleic acid (rRNA) transcription and assembly, is an important player in the cellular response to stress. Altered nucleolar function and morphology, including decreased nucleolar volume, has been observed in Parkinson's disease; thus the nucleolus represents a potential indicator of neurodegeneration in the disease. This study determined the effects of a partial unilateral intrastriatal 6-hydroxydopamine (6-OHDA) lesion, which models the dopaminergic loss found in Parkinson's disease, on the nucleoli of dopaminergic cells in the substantia nigra pars compacta (SNpc). Adult male Long-Evans rats underwent unilateral intrastriatal infusion of 6-OHDA (12.5μg). Lesions were verified by amphetamine-stimulated rotation 7 days later, and rats were euthanized 14 days after infusion. Coronal sections (50μm) were stained for tyrosine hydroxylase-silver nucleolar (TH-AgNOR) stain using MultiBrain Technology (NeuroScience Associates), which resulted in clearly defined nucleoli and neuronal outlines. Stereological methods were used to compare dopaminergic morphology between lesioned and intact hemispheres in each rat. In cells exhibiting a definable nucleolus, nucleolar volume was decreased by 16% on the ipsilateral side. The ipsilateral SNpc also exhibited an 18% decrease in SNpc planimetric volume, a 46% decrease in total TH-positive neuron number, and an 11% decrease in neuronal body volume (all P<0.05 by paired t-test). These findings suggest that the 6-OHDA lesion alters nucleolar morphology and that these changes are similar to those occurring in Parkinson's disease.
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Affiliation(s)
- Michelle Healy-Stoffel
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160, USA.
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Healy-Stoffel M, Ahmad SO, Stanford JA, Levant B. A novel use of combined tyrosine hydroxylase and silver nucleolar staining to determine the effects of a unilateral intrastriatal 6-hydroxydopamine lesion in the substantia nigra: a stereological study. J Neurosci Methods 2012; 210:187-94. [PMID: 22850559 PMCID: PMC3443281 DOI: 10.1016/j.jneumeth.2012.07.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Revised: 07/20/2012] [Accepted: 07/23/2012] [Indexed: 11/22/2022]
Abstract
Neurotoxic lesions of the nigrostriatal pathway model the deficits found in Parkinson's disease. This study used stereology and a novel staining method to examine the effects of a partial unilateral striatal 6-hydroxydopamine (6-OHDA) lesion on substantia nigra pars compacta (SNpc) dopamine neuron number and morphology in rats. Adult male Long-Evans rats were subjected to unilateral lesion of the SNpc by intrastriatal microinjection of 6-OHDA (12.5 μg). Lesions were verified by d-amphetamine-stimulated rotation (2.5 mg/kg, sc) by force-plate rotometry 7 days post-surgery. Seven days after rotation testing, rats were euthanized, and brains were prepared for either histology (n=12) or determination of striatal dopamine content by HPLC-EC (n=20). Brains prepared for histology were stained for tyrosine hydroxylase (TH) combined with a silver nucleolar (AgNOR) stain using a modified protocol developed for stereological assessment. The AgNOR counterstain allowed for precise definition of the nucleolus of the cells, facilitating both counting and qualitative morphometry of TH-positive neurons. Stereological quantitation determined a 54% decrease in TH-positive neuron number (P<0.01), and a 14% decrease in neuron volume (P<0.05) on the lesioned side. Striatal dopamine concentration was decreased by 92% (P<0.01), suggesting that striatal dopamine analysis may overestimate the numbers of SNpc neurons lost. These findings demonstrate that combined use of TH and AgNOR staining provides improved characterization of 6-OHDA-induced pathology. Furthermore, the data suggest that decreased neuronal volume as well as number contributes to the functional deficits observed after unilateral intrastriatal 6-OHDA lesion.
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Affiliation(s)
- Michelle Healy-Stoffel
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 USA
| | - S. Omar Ahmad
- Department of Occupational Therapy, Doisy College of Health Sciences, St. Louis University, St. Louis, MO 63104 USA
| | - John A. Stanford
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160 USA
| | - Beth Levant
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 USA
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Chen J, Levant B, Wang S. High-affinity and selective dopamine D₃ receptor full agonists. Bioorg Med Chem Lett 2012; 22:5612-7. [PMID: 22871578 DOI: 10.1016/j.bmcl.2012.07.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2012] [Revised: 06/27/2012] [Accepted: 07/02/2012] [Indexed: 12/29/2022]
Abstract
We have designed, synthesized and evaluated a series of new compounds with the goal to identify potent and selective D(3) ligands. The two most potent and selective new D(3) ligands are compounds 38 and 52, which bind to the D(3) receptors with a K(i) value of <nM and display a selectivity of 450-494 times over the D(2) receptors and >10,000 times over the D(1) receptors. Both 38 and 52 are full agonists with high potency at the D(3) receptor in a D(3) functional assay.
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Affiliation(s)
- Jianyong Chen
- Department of Internal Medicine, University of Michigan, 1500 East Medical Center Drive, Ann Arbor, MI 48109, USA
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17
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Chen J, Collins GT, Levant B, Woods J, Deschamps JR, Wang S. CJ-1639: A Potent and Highly Selective Dopamine D3 Receptor Full Agonist. ACS Med Chem Lett 2011; 2:620-625. [PMID: 22125662 DOI: 10.1021/ml200100t] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
We have identified several ligands with high binding affinities to the dopamine D3 receptor and excellent selectivity over the D2 and D1 receptors. CJ-1639 (17) binds to the D3 receptor with a K(i) value of 0.50 nM and displays a selectivity of >5,000 times over D2 and D1 receptors in binding assays using dopamine receptors expressed in the native rat brain tissues. CJ-1639 binds to human D3 receptor with a K(i) value of 3.61 nM and displays over >1000-fold selectivity over human D1 and D2 receptors. CJ-1639 is active at 0.01 mg/kg at the dopamine D3 receptor in the rat and only starts to show a modest D2 activity at doses as high as 10 mg/kg. CJ-1639 is the most potent and selective D3 full agonist reported to date.
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Affiliation(s)
| | | | - Beth Levant
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160, United States
| | | | - Jeffrey R. Deschamps
- Center for Biomolecular Science and Engineering, Naval Research Laboratory, 4555 Overlook Avenue, Washington, DC 20375, United States
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18
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Collins GT, Truong YNT, Levant B, Chen J, Wang S, Woods JH. Behavioral sensitization to cocaine in rats: evidence for temporal differences in dopamine D3 and D2 receptor sensitivity. Psychopharmacology (Berl) 2011; 215:609-20. [PMID: 21207013 PMCID: PMC3102773 DOI: 10.1007/s00213-010-2154-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Accepted: 12/15/2010] [Indexed: 11/27/2022]
Abstract
RATIONALE Cocaine-induced changes in D(2) receptors have been implicated in the expression of sensitized behavioral responses and addiction-like behaviors; however, the influence of D(3) receptors is less clear. OBJECTIVES To characterize the effects of repeated cocaine administration on the sensitivity of rats to D(2)- and D(3)-mediated behaviors, as well as the binding properties of ventral striatal D(2)-like and D(3) receptors. METHODS Pramipexole was used to assess the sensitivity of rats to D(3)/D(2) agonist-induced yawning, hypothermia, and locomotor activity, 24 h, 72 h, 10, 21, and 42 days after repeated cocaine or saline administration. The locomotor effects of cocaine (42 day) and the binding properties of ventral striatal D(2)-like and D(3) receptors (24 h and 42 days) were also evaluated. RESULTS Cocaine-treated rats displayed an enhanced locomotor response to cocaine, as well as a progressive and persistent leftward/upward shift of the ascending limb (72 h-42 day) and leftward shift of the descending limb (42 days) of the pramipexole-induced yawning dose-response curve. Cocaine treatment also decreased B (max) and K (d) for D(2)-like receptors and increased D(3) receptor binding at 42 days. Cocaine treatment did not change pramipexole-induced hypothermia or locomotor activity or yawning induced by cholinergic or serotonergic agonists. CONCLUSIONS These studies suggest that temporal differences exist in the development of cocaine-induced sensitization of D(3) and D(2) receptors, with enhancements of D(3)-mediated behavioral effects observed within 72 h and enhancements of D(2)-mediated behavioral effects apparent 42 days after cocaine. These findings highlight the need to consider changes in D(3) receptor function when thinking about the behavioral plasticity that occurs during abstinence from cocaine use.
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Affiliation(s)
- Gregory T. Collins
- Department of Pharmacology, 1301 MSRB III, 1150 W. Medical Center Drive, University of Michigan Medical School, Ann Arbor, MI 48109-0632, USA
| | - Yen Nhu-Thi Truong
- Department of Pharmacology, 1301 MSRB III, 1150 W. Medical Center Drive, University of Michigan Medical School, Ann Arbor, MI 48109-0632, USA
| | - Beth Levant
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Jianyong Chen
- Departments of Internal Medicine and Medicinal Chemistry, University of Michigan Medical School, Ann Arbor, MI 48109-0934, USA
| | - Shaomeng Wang
- Department of Pharmacology, 1301 MSRB III, 1150 W. Medical Center Drive, University of Michigan Medical School, Ann Arbor, MI 48109-0632, USA. Departments of Internal Medicine and Medicinal Chemistry, University of Michigan Medical School, Ann Arbor, MI 48109-0934, USA
| | - James H. Woods
- Department of Pharmacology, 1301 MSRB III, 1150 W. Medical Center Drive, University of Michigan Medical School, Ann Arbor, MI 48109-0632, USA
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Russell KL, Kutchko KM, Fowler SC, Berman NEJ, Levant B. Sensorimotor behavioral tests for use in a juvenile rat model of traumatic brain injury: assessment of sex differences. J Neurosci Methods 2011; 199:214-22. [PMID: 21600923 DOI: 10.1016/j.jneumeth.2011.05.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Revised: 04/29/2011] [Accepted: 05/04/2011] [Indexed: 12/23/2022]
Abstract
Modeling juvenile traumatic brain injury (TBI) in rodents presents several unique challenges compared to adult TBI, one of which is selecting appropriate sensorimotor behavioral tasks that enable the assessment of the extent of injury and recovery over time in developing animals. To address this challenge, we performed a comparison of common sensorimotor tests in Long-Evans rats of various sizes and developmental stages (postnatal days 16-45, 35-190 g). Tests were compared and selected for their developmental appropriateness, scalability for growth, pre-training requirements, and throughput capability. Sex differences in response to TBI were also assessed. Grid walk, automated gait analysis, rotarod, beam walk, spontaneous forelimb elevation test, and measurement of motor activity using the force-plate actometer were evaluated. Grid walk, gait analysis, and rotarod failed to meet one or more of the evaluation criteria. Beam walk, spontaneous forelimb elevation test, and measurement of motor activity using the force-plate actometer satisfied all criteria and were capable of detecting motor abnormalities in rats subjected to controlled cortical impact on postnatal day 17. No sex differences were detected in the acute effects of TBI or functional recovery during the 28 days after injury using these tests. This demonstrates the utility of these tests for the evaluation of sensorimotor function in studies using rat models of pediatric TBI, and suggests that pre-pubertal males and females respond similarly to TBI with respect to sensorimotor outcomes.
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Affiliation(s)
- Kristin L Russell
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160, USA.
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20
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Raveendran VV, Tan X, Sweeney ME, Levant B, Slusser J, Stechschulte DJ, Dileepan KN. Lipopolysaccharide induces H1 receptor expression and enhances histamine responsiveness in human coronary artery endothelial cells. Immunology 2011; 132:578-88. [PMID: 21255012 DOI: 10.1111/j.1365-2567.2010.03403.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Summary Histamine is a well-recognized modulator of vascular inflammation. We have shown that histamine, acting via H1 receptors (H1R), synergizes lipopolysaccharide (LPS)-induced production of prostaglandin I(2) (PGI(2)), PGE(2) and interleukin-6 (IL-6) by endothelial cells. The synergy between histamine and LPS was partly attributed to histamine -induced expression of Toll-like receptor 4 (TLR4). In this study, we examined whether LPS stimulates the H1R expression in human coronary artery endothelial cells (HCAEC) with resultant enhancement of histamine responsiveness. Incubation of HCAEC with LPS (10-1000 ng/ml) resulted in two-fold to fourfold increases in H1R mRNA expression in a time-dependent and concentration-dependent fashion. In contrast, LPS treatment did not affect H2R mRNA expression. The LPS-induced H1R mRNA expression peaked by 4 hr after LPS treatment and remained elevated above the basal level for 20-24 hr. Flow cytometric and Western blot analyses revealed increased expression of H1R protein in LPS-treated cells. The specific binding of [(3)H]pyrilamine to H1R in membrane proteins from LPS-treated HCAEC was threefold higher than the untreated cells. The LPS-induced H1R expression was mediated through TLR4 as gene silencing by TLR4-siRNA and treatment with a TLR4 antagonist inhibited the LPS effect. When HCAEC were pre-treated with LPS for 24 hr, washed and challenged with histamine, 17-, 10- and 15-fold increases in PGI(2), PGE(2) and IL-6 production, respectively, were noted. Histamine-induced enhancement of the synthesis of PGI(2), PGE(2) and IL-6 by LPS-primed HCAEC was completely blocked by an H1R antagonist. The results demonstrate that LPS, through TLR4 activation, up-regulates the expression and function of H1R and amplifies histamine-induced inflammatory responses in HCAEC.
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Affiliation(s)
- Vineesh V Raveendran
- Division of Allergy, Clinical Immunology and Rheumatology, Department of Medicine, University of Kansas Medical Center, Kansas City, KS 66160, USA
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21
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Levant B, Zarcone TJ, Davis PF, Ozias MK, Fowler SC. Differences in methylphenidate dose response between periadolescent and adult rats in the familiar arena-novel alcove task. J Pharmacol Exp Ther 2010; 337:83-91. [PMID: 21205916 DOI: 10.1124/jpet.110.174425] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Methylphenidate is a psychostimulant widely used in the treatment of attention deficit hyperactivity disorder. In this study, the effects of two nonstereotypy-inducing doses of methylphenidate (2.5 and 5.0 mg/kg s.c.) were examined in periadolescent [postnatal days (P) 35 and 42] and young adult (P70), male Long-Evans rats using a three-period locomotor activity paradigm that affords inferences about exploration, habituation, and attention to a novel stimulus (an "alcove") in a familiar environment in a single test session. In the first test period, P35 and P42 rats were more active than P70 rats, and methylphenidate increased locomotion in a dose-related manner. The introduction of a novel spatial stimulus in the third test period revealed a significant interaction of dose and age such that P70 rats exhibited dose-related increases in distance traveled, but P35 rats did not. Furthermore, methylphenidate dose-relatedly disrupted the rats' tendency to spend increasing amounts of time in the alcove across the test period at P70 but not at P35. Brain and serum methylphenidate concentrations were significantly lower at P35 than at P70, with intermediate levels at P42. Developmental differences in dopaminergic neurochemistry were also observed, including increased dopamine content in the caudate-putamen, nucleus accumbens, and frontal cortex and decreased densities of D(1)-like receptors in the frontal cortex in P70 than in P42 rats. These results raise the possibility that children and adults may respond differently when treated with this drug, particularly in situations involving response to novelty and that these effects involve developmental differences in pharmacokinetics and dopaminergic neurochemistry.
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Affiliation(s)
- Beth Levant
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Mail Stop 1018, 3901 Rainbow Blvd., Kansas City, KS 66160, USA.
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22
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Levant B. N-3 (omega-3) Fatty acids in postpartum depression: implications for prevention and treatment. Depress Res Treat 2010; 2011:467349. [PMID: 21151517 PMCID: PMC2989696 DOI: 10.1155/2011/467349] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Accepted: 09/21/2010] [Indexed: 12/22/2022]
Abstract
A growing body of clinical and epidemiological evidence suggests that low dietary intake and/or tissue levels of n-3 (omega-3) polyunsaturated fatty acids (PUFAs) are associated with postpartum depression. Low tissue levels of n-3 PUFAs, particularly docosahexaenoic acid (DHA), are reported in patients with either postpartum or nonpuerperal depression. Moreover, the physiological demands of pregnancy and lactation put childbearing women at particular risk of experiencing a loss of DHA from tissues including the brain, especially in individuals with inadequate dietary n-3 PUFA intake or suboptimal metabolic capabilities. Animal studies indicate that decreased brain DHA in postpartum females leads to several depression-associated neurobiological changes including decreased hippocampal brain-derived neurotrophic factor and augmented hypothalamic-pituitary-adrenal responses to stress. Taken together, these findings support a role for decreased brain n-3 PUFAs in the multifactorial etiology of depression, particularly postpartum depression. These findings, and their implications for research and clinical practice, are discussed.
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Affiliation(s)
- Beth Levant
- Department of Pharmacology, Toxicology, and Therapeutics, Kansas Intellectual and Developmental Disabilities Research Center, The University of Kansas Medical Center, MS-1018, 3901 Rainbow Boulevard., Kansas City, KS 66160, USA
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Levant B, Zarcone TJ, Fowler SC. Developmental effects of dietary n-3 fatty acids on activity and response to novelty. Physiol Behav 2010; 101:176-83. [PMID: 20457171 PMCID: PMC2923479 DOI: 10.1016/j.physbeh.2010.04.038] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Revised: 04/16/2010] [Accepted: 04/29/2010] [Indexed: 02/05/2023]
Abstract
Insufficient availability of n-3 polyunsaturated fatty acids (PUFA) during pre- and neonatal development decreases accretion of docosahexaenoic acid (DHA, 22:6n-3) in the developing brain. Low tissue levels of DHA are associated with neurodevelopmental disorders including attention deficit hyperactivity disorder (ADHD). In this study, 1st- and 2nd-litter male Long-Evans rats were raised from conception on a Control diet containing alpha-linolenic acid (4.20 g/kg diet), the dietarily essential fatty acid precursor of DHA, or a diet Deficient in alpha-linolenic acid (0.38 g/kg diet). The Deficient diet resulted in a decrease in brain phospholipid DHA of 48% in 1st-litter pups and 65% in 2nd-litter pups. Activity, habituation, and response to spatial change in a familiar environment were assessed in a single-session behavioral paradigm at postnatal days 28 and 70, inclusive. Activity and habituation varied by age with younger rats exhibiting higher activity, less habituation, and less stimulation of activity induced by spatial novelty. During the first and second exposures to the test chamber, 2nd-litter Deficient pups exhibited higher levels of activity than Control rats or 1st-litter Deficient pups, and less habituation during the first exposure, but were not more active after introduction of a novel spatial stimulus. The higher level of activity in a familiar environment, but not after introduction of a novel stimulus is consistent with clinical observations in ADHD. The observation of this effect only in 2nd-litter rats fed the Deficient diet suggests that brain DHA content, rather than dietary n-3 PUFA content, likely underlies these effects.
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Affiliation(s)
- Beth Levant
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160, USA.
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24
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Davis PF, Ozias MK, Carlson SE, Reed GA, Winter MK, McCarson KE, Levant B. Dopamine receptor alterations in female rats with diet-induced decreased brain docosahexaenoic acid (DHA): interactions with reproductive status. Nutr Neurosci 2010; 13:161-9. [PMID: 20670471 PMCID: PMC2955509 DOI: 10.1179/147683010x12611460764282] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2009] [Revised: 10/02/2009] [Accepted: 10/26/2009] [Indexed: 12/11/2022]
Abstract
Decreased tissue levels of n-3 (omega-3) fatty acids, particularly docosahexaenoic acid (DHA), are implicated in the etiologies of non-puerperal and postpartum depression. This study examined the effects of a diet-induced loss of brain DHA content and concurrent reproductive status on dopaminergic parameters in adult female Long-Evans rats. An alpha-linolenic acid-deficient diet and breeding protocols were used to produce virgin and parous female rats with cortical phospholipid DHA levels 20-22% lower than those fed a control diet containing adequate alpha-linolenic acid. Decreased brain DHA produced a significant main effect of decreased density of ventral striatal D(2)-like receptors. Virgin females with decreased DHA also exhibited higher density of D(1)-like receptors in the caudate nucleus than virgin females with normal DHA. These receptor alterations are similar to those found in several rodent models of depression, and are consistent with the proposed hypodopaminergic basis for anhedonia and motivational deficits in depression.
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Affiliation(s)
- Paul F. Davis
- Department of Pharmacology, Toxicology, and Therapeutics
| | | | - Susan E. Carlson
- Department of Dietetics & Nutrition
- Kansas Intellectual and Developmental Disabilities Research Center, University of Kansas Medical Center. Kansas City, Kansas, USA
| | | | - Michelle K. Winter
- Department of Pharmacology, Toxicology, and Therapeutics
- Kansas Intellectual and Developmental Disabilities Research Center, University of Kansas Medical Center. Kansas City, Kansas, USA
| | - Kenneth E. McCarson
- Department of Pharmacology, Toxicology, and Therapeutics
- Kansas Intellectual and Developmental Disabilities Research Center, University of Kansas Medical Center. Kansas City, Kansas, USA
| | - Beth Levant
- Department of Pharmacology, Toxicology, and Therapeutics
- Kansas Intellectual and Developmental Disabilities Research Center, University of Kansas Medical Center. Kansas City, Kansas, USA
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25
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Vimala Raveendran V, Tan X, Levant B, Stechschulte D, Dileepan K. Lipopolysaccharide induces H1 receptor expression and enhances histamine responsiveness in human coronary artery endothelial cells (35.10). The Journal of Immunology 2010. [DOI: 10.4049/jimmunol.184.supp.35.10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Histamine (HIS) is a well-recognized modulator of vascular inflammation. We have shown that HIS, acting via H1 receptors (H1R), synergizes LPS-induced production of IL-6, IL-8, PGE2 and PGI2 by endothelial cells. The synergy between HIS and LPS was partly attributed to HIS-induced expression of TLR4. In this study, we examined whether LPS stimulates the H1R expression in human coronary artery endothelial cells (HCAEC) and enhances HIS responsiveness. Incubation of HCAEC with LPS (10-1000 ng/ml) resulted in 2- to 4-fold increases in H1R mRNA expression in a time and concentration-dependent fashion. In contrast, LPS treatment did not affect H2R mRNA expression. LPS-induced H1R expression was maximum at 4h after LPS treatment which returned to the basal level by 8h. The LPS-induced H1R gene expression was mediated through TLR4 because gene silencing by TLR4-siRNA inhibited LPS effect. The specific binding of [3H]-pyrilamine to H1R in membrane proteins from LPS-treated HCAEC was 3-fold higher than the untreated cells. When HCAEC were pretreated with LPS for 24h, washed and subsequently challenged with HIS, 15-, 17- and 10-fold increases in IL-6, PGI2 and PGE2 production, respectively, were noted. HIS-induced syntheses of IL-6, PGE2 and PGI2 by LPS-primed HCAEC were completely blocked by the H1R antagonist cetirizine. These results demonstrate that LPS upregulates the expression and function of H1R in HCAEC leading to agonist-induced increase in IL-6, PGI2 and PGE2 production.
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Affiliation(s)
| | - Xiaoyu Tan
- 1University of Kansas Medical Center, Kansas City, KS
| | - Beth Levant
- 1University of Kansas Medical Center, Kansas City, KS
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26
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Oien DB, Ortiz AN, Rittel AG, Dobrowsky RT, Johnson MA, Levant B, Fowler SC, Moskovitz J. Dopamine D(2) receptor function is compromised in the brain of the methionine sulfoxide reductase A knockout mouse. J Neurochem 2010; 114:51-61. [PMID: 20374422 DOI: 10.1111/j.1471-4159.2010.06721.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Previous research suggests that brain oxidative stress and altered rodent locomotor behavior are linked. We observed bio-behavioral changes in methionine sulfoxide reductase A knockout mice associated with abnormal dopamine signaling. Compromised ability of these knockout mice to reduce methionine sulfoxide enhances accumulation of sulfoxides in proteins. We examined the dopamine D(2)-receptor function and expression, which has an atypical arrangement and quantity of methionine residues. Indeed, protein expression levels of dopamine D(2)-receptor were higher in knockout mice compared with wild-type. However, the binding of dopamine D(2)-receptor agonist was compromised in the same fractions of knockout mice. Coupling efficiency of dopamine D(2)-receptors to G-proteins was also significantly reduced in knockout mice, supporting the compromised agonist binding. Furthermore, pre-synaptic dopamine release in knockout striatal sections was less responsive than control sections to dopamine D(2)-receptor ligands. Behaviorally, the locomotor activity of knockout mice was less responsive to the inhibitory effect of quinpirole than wild-type mice. Involvement of specific methionine residue oxidation in the dopamine D(2)-receptor third intracellular loop is suggested by in vitro studies. We conclude that ablation of methionine sulfoxide reductase can affect dopamine signaling through altering dopamine D(2)-receptor physiology and may be related to symptoms associated with neurological disorders and diseases.
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Affiliation(s)
- Derek B Oien
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, Kansas 66045, USA
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27
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Fowler SC, Zarcone TJ, Levant B. Methylphenidate attenuates rats' preference for a novel spatial stimulus introduced into a familiar environment: assessment using a force-plate actometer. J Neurosci Methods 2010; 189:36-43. [PMID: 20346982 DOI: 10.1016/j.jneumeth.2010.03.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2009] [Revised: 03/15/2010] [Accepted: 03/16/2010] [Indexed: 10/19/2022]
Abstract
Methylphenidate is a psychostimulant widely used in the treatment of attention deficit hyperactivity disorder (ADHD). Here we report a novel paradigm that affords inferences about habituation and attention to a novel stimulus in a familiar environment in a single test session without prior training of the animals. The paradigm was used to assess the effects of methylphenidate (2.5 and 5.0mg/kg, sc) in young adult, male, Long-Evans rats. Methylphenidate increased locomotor activity during the initial exposure to the test apparatus in a non-dose-related manner. However, upon introduction of a novel spatial stimulus (an alcove) in the familiar environment, methylphenidate-treatment resulted in dose-related increases in distance traveled and inhibition of long dwell times in the alcove, the latter behavior being characteristic of vehicle-treated rats' response to the alcove condition. These results demonstrate the utility of this paradigm in the elucidation of the behavioral effects of a drug commonly used in the treatment of ADHD. Findings also suggest that species-typical response preferences in rats (e.g., refuge-seeking) may emerge in experimental settings that add spatial novelty to otherwise featureless test enclosures commonly used to assess locomotor activity.
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Affiliation(s)
- Stephen C Fowler
- Department of Pharmacology & Toxicology, University of Kansas, Lawrence, KS 66045, USA
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28
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Levant B, Ozias MK, Davis PF, Winter M, Russell KL, Carlson SE, Reed GA, McCarson KE. Decreased brain docosahexaenoic acid content produces neurobiological effects associated with depression: Interactions with reproductive status in female rats. Psychoneuroendocrinology 2008; 33:1279-92. [PMID: 18707812 PMCID: PMC2582014 DOI: 10.1016/j.psyneuen.2008.06.012] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2007] [Revised: 04/28/2008] [Accepted: 06/11/2008] [Indexed: 11/27/2022]
Abstract
Decreased tissue levels of docosahexaenoic acid (DHA; 22:6n-3) are implicated in the etiologies of non-puerperal and postpartum depression. With the aim of determining neurobiological sequelae of decreased brain DHA content, this study examined the effects of a loss of brain DHA content and concurrent reproductive status in adult female Long-Evans rats. An alpha-linolenic acid-deficient diet and breeding protocols were used to produce virgin and parous female rats with cortical phospholipid DHA levels 23-26% lower than virgin and parous rats fed a control diet containing adequate alpha-linolenic acid. Parous dams were tested/euthanized at weaning (postnatal day 20) of the second litter; virgin females, during diestrus. Decreased brain DHA was associated with decreased hippocampal BDNF gene expression and increased relative corticosterone response to an intense stressor, regardless of reproductive status. In virgin females with decreased brain DHA, serotonin content and turnover in frontal cortex were decreased compared to virgin females with normal brain DHA. In parous dams with decreased brain DHA, the density of 5-HT(1A) receptors in the hippocampus was increased, corticosterone response to an intense stressor was increased, and the latency to immobility in the forced swim test was decreased compared to parous dams with normal DHA. These findings demonstrate neurobiological alterations attributable to decreased brain DHA or an interaction of parous status and brain DHA level. Furthermore, the data are consistent with findings in depressed humans, and thus support a role for DHA as a factor in the etiologies of depressive illnesses, particularly postpartum depression.
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Affiliation(s)
- Beth Levant
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160, USA.
| | - Marlies K. Ozias
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 USA
| | - Paul F. Davis
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 USA
| | - Michelle Winter
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 USA
| | - Kristin L. Russell
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 USA
| | - Susan E. Carlson
- Department of Dietetics & Nutrition, University of Kansas Medical Center, Kansas City, KS 66160 USA,Department of Pediatrics, University of Kansas Medical Center, Kansas City, KS 66160 USA,The Kansas Intellectual and Developmental Disabilities Research Center, University of Kansas Medical Center, Kansas City, KS 66160 USA
| | - Gregory A. Reed
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 USA
| | - Kenneth E. McCarson
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 USA,The Kansas Intellectual and Developmental Disabilities Research Center, University of Kansas Medical Center, Kansas City, KS 66160 USA
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29
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Chen J, Collins GT, Zhang J, Yang CY, Levant B, Woods J, Wang S. Design, synthesis, and evaluation of potent and selective ligands for the dopamine 3 (D3) receptor with a novel in vivo behavioral profile. J Med Chem 2008; 51:5905-8. [PMID: 18785726 DOI: 10.1021/jm800471h] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A series of compounds structurally related to pramipexole were designed, synthesized, and evaluated as ligands for the dopamine 3 (D3) receptor. Compound 12 has a K(i) value of 0.41 nM to D3 and a selectivity of >30000- and 800-fold over the D1-like and D2 receptors, respectively. Our in vivo functional assays showed that this compound is a partial agonist at the D3 receptor with no detectable activity at the D2 receptor.
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Affiliation(s)
- Jianyong Chen
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan 48109, USA
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30
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Culver KE, Szechtman H, Levant B. Altered dopamine D2-like receptor binding in rats with behavioral sensitization to quinpirole: effects of pre-treatment with Ro 41-1049. Eur J Pharmacol 2008; 592:67-72. [PMID: 18644362 DOI: 10.1016/j.ejphar.2008.06.101] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2008] [Revised: 06/20/2008] [Accepted: 06/27/2008] [Indexed: 11/18/2022]
Abstract
Repeated treatment with the dopamine D2/D3 receptor agonist quinpirole produces a sensitized behavioral response in rats manifested as an increase in locomotor activity. Pre-treatment with certain monoamine oxidase inhibitors, such as Ro 41-1049 [N-(2-aminomethyl)-5-(3-fluorophenyl)-4-thiazolecarboxamide HCl], changes the sensitized response from locomotion to stationary, self-directed mouthing. In this study, the effects of quinpirole sensitization, with and without pre-treatment with Ro 41-1049, were determined on dopamine D2-like receptors in the nucleus accumbens and the striatum. Long-Evans rats were pre-treated with Ro 41-1049 (1 mg/kg) 90 min prior to administration of quinpirole (0.5 mg/kg, 8 injections, every 3-4 days). Dopamine D2-like receptor binding was determined 3 days after the last injection by ex vivo radioligand assays using [3H]spiperone and [3H]quinpirole. Densities of [3H]spiperone- and [3H]quinpirole-labeled sites were both increased 32% in the nucleus accumbens of rats with demonstrated locomotor sensitization to quinpirole. In contrast, the density of dopamine D2-like receptors in quinpirole-sensitized rats pre-treated with Ro 41-1049 was not different from saline controls. These findings support the involvement of alterations in dopamine D2-like receptors in the development of locomotor sensitization to quinpirole and suggest that modification of these alterations in dopamine D2-like receptors contributes to the change from sensitized locomotion to mouthing observed when rats are pre-treated with Ro 41-1049.
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Affiliation(s)
- Kirsten E Culver
- School of Nursing, McMaster University, Hamilton, Ontario, Canada
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31
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Witkin JM, Levant B, Zapata A, Kaminski R, Gasior M. The dopamine D3/D2 agonist (+)-PD-128,907 [(R-(+)-trans-3,4a,10b-tetrahydro-4-propyl-2H,5H-[1]benzopyrano[4,3-b]-1,4-oxazin-9-ol)] protects against acute and cocaine-kindled seizures in mice: further evidence for the involvement of D3 receptors. J Pharmacol Exp Ther 2008; 326:930-8. [PMID: 18566292 DOI: 10.1124/jpet.108.139212] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Previous findings have demonstrated a protective role for dopamine D(3)/D(2) receptor agonists in the convulsant and lethal effects of acutely administered cocaine. Data are provided here to establish that the protection occurs through a D(3)-linked mechanism and that protection is extended to seizure kindling. The D(3) antagonist SB-277011-A [4-quinolinecarboxamide,N-[trans-4-[2-(6-cyano-3,4-dihydro-2(1H)-isoquinolinyl)ethyl]-cyclohexyl]-(9CI)] prevented the anticonvulsant effect of the D(3)/D(2) receptor agonist (+)-PD-128,907 [(R-(+)-trans-3,4a,10b-tetrahydro-4-propyl-2H,5H-[1]benzopyrano[4,3-b]-1,4-oxazin-9-ol)] on cocaine-induced seizures. The protection afforded by the D(3)/D(2) agonist, (+)-PD-128,907, was eliminated in D(3) receptor-deficient mice. In D(2) receptor knockout mice, the anticonvulsant effects of (+)-PD-128,907 were preserved. (+)-PD-128,907 also prevented the acquisition and expression of cocaine-kindled seizures engendered by repeated daily dosing with 60 mg/kg cocaine. (+)-PD-128,907 also blocked the seizures induced in mice fully seizure kindled to cocaine. Although repeated dosing with cocaine increased the potency of cocaine to produce seizures and lethality (decreased ED(50) values), daily coadministration of (+)-PD-128,907 significantly prevented this potency shift. In mice treated daily with cocaine and (+)-PD-128,907, the density, but not the affinity, of D(3) receptors was increased. The specificity with which (+)-PD-128,907 acts upon this cocaine-driven process was demonstrated by the lack of a significant effect of (+)-PD-128,907 on seizure kindling to a GABA(A) receptor antagonist, pentylenetetrazol. Taken together and with literature findings, the data indicate that dopamine D(3) receptors function in the initiation of a dampening mechanism against the toxic effects of cocaine, a finding that might have relevance to psychiatric disorders of drug dependence, schizophrenia, and bipolar depression.
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Affiliation(s)
- J M Witkin
- Psychiatric Drug Discovery, Lilly Research Laboratories, Lilly Corporate Center, Indianapolis, IN 46285-0501, USA.
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32
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Ahmad SO, Park JH, Radel JD, Levant B. Reduced numbers of dopamine neurons in the substantia nigra pars compacta and ventral tegmental area of rats fed an n-3 polyunsaturated fatty acid-deficient diet: a stereological study. Neurosci Lett 2008; 438:303-7. [PMID: 18499349 DOI: 10.1016/j.neulet.2008.04.073] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2008] [Revised: 04/17/2008] [Accepted: 04/18/2008] [Indexed: 11/25/2022]
Abstract
Inadequate dietary n-3 polyunsaturated fatty acid (PUFA) content is associated with altered function of the CNS dopamine systems. In this study, the effects of dietary n-3 PUFA content were determined on dopamine cell number and morphology. Adult (postnatal day 70), male, Long-Evans rats were raised from conception on diets containing adequate (control) or negligible n-3 PUFAs. The number and morphology of tyrosine hydroxylase-positive cells in the substantia nigra pars compacta and ventral tegmental area were determined stereologically. The number of tyrosine hydroxylase-positive cells in rats fed the n-3 PUFA-deficient diet was 33.9% lower in the substantia nigra pars compacta and 33.7% lower in the ventral tegmental area than in those fed the control diet (P<0.05); however, the volume of tyrosine hydroxylase-positive cell bodies was not different between diet groups in either brain region. Rats fed the n-3 PUFA-deficient diet also exhibited dendritic depletion and isolation of tyrosine hydroxylase-positive cells compared to rats fed the control diet, which had clustering of tyrosine hydroxylase-positive cells and extensive dendritic arborization. These findings support a role for n-3 PUFAs in the survival of dopamine neurons and suggest that altered dopamine cell number, as well as function, contributes to the behavioral effects observed in rats raised on n-3 PUFA-deficient diets.
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Affiliation(s)
- S Omar Ahmad
- Department of Occupational Therapy Education, University of Kansas Medical Center, Kansas City, KS 66160, USA
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33
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Levant B, Ozias MK, Carlson SE. Diet (n-3) polyunsaturated fatty acid content and parity affect liver and erythrocyte phospholipid fatty acid composition in female rats. J Nutr 2007; 137:2425-30. [PMID: 17951480 DOI: 10.1093/jn/137.11.2425] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The fatty acid composition of membrane phospholipids affects the physicochemical properties of the membrane and thus influences cell function. In this study, the effects of 1-4 sequential pregnancies on the phospholipid fatty acid compositions of the maternal liver and erythrocytes were determined in female rats fed diets containing alpha-linolenic acid (ALA), ALA and preformed docosahexaenoic acid (DHA; ALA+DHA), or minimal ALA (low ALA). Virgin females, fed the diets for commensurate durations, served as a control for reproduction. Liver and erythrocyte total phospholipid compositions were determined at weaning by TLC/GC. In both tissues, significant main effects of diet and reproductive status were detected for many fatty acids, but a significant interaction of diet, reproductive status, and duration of treatment (no. of reproductive cycles or equivalent time period for virgins) was detected only for DHA, 22:6(n-3). Primiparous dams fed the ALA and low ALA diet had decreased liver DHA content of 31% and 74%, respectively, compared with virgin females fed the ALA diet. Liver DHA did not decrease further after additional reproductive cycles. Liver DHA content was unchanged in parous dams fed the ALA+DHA diet, but virgin females fed this diet exhibited a 50% increase in liver DHA after 13 wk of treatment. Changes in erythrocyte DHA were of similar magnitude and time course to those observed in liver, suggesting that this tissue may serve as a marker for liver DHA status.
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Affiliation(s)
- Beth Levant
- Department of Pharmacology, University of Kansas Medical Center, Kansas City, KS 66160, USA.
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34
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Richards TL, Pazdernik TL, Levant B. Basal local cerebral glucose utilization is not altered after behavioral sensitization to quinpirole. Neurosci Lett 2007; 429:165-8. [PMID: 17997222 DOI: 10.1016/j.neulet.2007.10.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2007] [Revised: 10/03/2007] [Accepted: 10/09/2007] [Indexed: 11/28/2022]
Abstract
Sensitization to psychostimulants results in a behavioral response of a greater magnitude than that produced by a given single dose. Previously, we have shown that sensitization to the D(2)/D(3) dopamine receptor agonist quinpirole produces alterations in quinpirole-stimulated local cerebral glucose utilization (LCGU) in ventral striatal and limbic cortical regions. To determine whether basal neuronal activity is altered in the sensitized animal, this study examined the effects of a sensitizing course of quinpirole on basal neuronal activity using the [(14)C]-2-deoxyglucose (2-DG) method in rats with verified sensitization. Adult, male Long-Evans rats (n = 7 or 10/group) were subjected to 10 injections of quinpirole (0.5 mg/kg, s.c.) or saline administered every 3rd day. Sensitization was verified on the basis of locomotor activity. The 2-DG procedure was performed in freely moving rats 3 days after the last quinpirole injection. LCGU was determined by quantitative autoradiography. No alterations in basal LCGU were detected in quinpirole-sensitized rats compared to those treated with saline. The present finding suggests that either the basal activity of very discrete populations of neurons is affected by sensitization to quinpirole that are not likely to be detected by the 2-DG method, or that the neurobiological changes that result in the sensitized behavioral response affect only stimulated, but not basal, neuronal activity.
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Affiliation(s)
- Toni L Richards
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160, USA
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35
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Richards TL, Pazdernik TL, Levant B. Clorgyline-induced modification of behavioral sensitization to quinpirole: effects on local cerebral glucose utilization. Brain Res 2007; 1160:124-33. [PMID: 17573047 PMCID: PMC2099299 DOI: 10.1016/j.brainres.2007.05.035] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2007] [Revised: 05/15/2007] [Accepted: 05/17/2007] [Indexed: 11/18/2022]
Abstract
Sensitization refers to augmented behavioral responses produced by repeated, intermittent injections of dopaminergic psychostimulants. The locomotor manifestations observed after a sensitizing course of quinpirole, a D(2)/D(3) dopamine agonist, can be modified by the MAO(A) inhibitor clorgyline, by a mechanism apparently unrelated to its actions on MAO(A). Alterations in regional neuronal activity produced by quinpirole in quinpirole-sensitized rats with or without clorgyline pretreatment were assessed based on LCGU using the [(14)C]-2-deoxyglucose (2-DG) method. Adult, male Long-Evans rats (180-200 g, n=9-10/group) were subjected to an injection of either clorgyline (1.0 mg/kg, s.c.) or saline 90 min prior to an injection of quinpirole (0.5 mg/kg, s.c.) or saline, 1 set of injections administered every 3rd day for 10 sets. The 2-DG procedure was initiated 60 min after an 11th set of injections in freely moving rats. LCGU was determined by quantitative autoradiography. LCGU was decreased in a number of limbic (nucleus accumbens and ventral pallidum) and cortical (medial/ventral orbital and infralimbic) regions and in the raphe magnus nucleus in quinpirole-sensitized rats (P<0.05 vs. saline-saline). Quinpirole-sensitized rats pretreated with clorgyline had similar alterations in LCGU, but LCGU was higher in the locus coeruleus compared to quinpirole alone (P<0.05), was not decreased in the raphe magnus nucleus, and was decreased in the piriform cortex and septum. This implicates altered activity of the noradrenergic, serotonergic, olfactory, and limbic systems in the modified behavioral response to quinpirole with clorgyline pretreatment.
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Affiliation(s)
- Toni L Richards
- Department of Pharmacology, University of Kansas Medical Center, Kansas City, KS 66160-7417, USA
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36
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Affiliation(s)
- Beth Levant
- The University of Kansas Medical Center Kansas City Kansas
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37
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Pierce JD, Jegathesan J, Levant B, Winter M, McCarson KE, Clancy RL. Detection of dopamine receptor subtypes in the rat diaphragm. Heart Lung 2007; 36:58-63. [PMID: 17234478 DOI: 10.1016/j.hrtlng.2006.05.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2006] [Revised: 04/15/2006] [Accepted: 05/15/2006] [Indexed: 11/16/2022]
Abstract
BACKGROUND The administration of dopamine using an in vivo animal model has been shown to prevent and treat diaphragm fatigue. OBJECTIVE With the knowledge that dopamine stimulates alpha- and beta-adrenergic and dopamine receptors, the purpose of this study was to investigate whether dopamine receptors are present in the diaphragm. In addition, if dopamine receptors were detected, we would identify the class and subtype of dopamine receptors. METHOD Radioligand binding studies and reverse transcriptase polymerase chain reaction experiments were used. RESULTS The receptor binding studies were unable to establish whether dopamine receptors were present in the diaphragm. However, highly sensitive reverse transcriptase polymerase chain reaction experiments demonstrated that D(1)-like receptors (D(1) and D(5) receptors) were detected in the diaphragm. CONCLUSIONS This study is the first to report the class and specific subtype of dopamine receptors found in the diaphragm. By identifying dopamine receptors in the diaphragm, we have a better understanding of the mechanisms by which dopamine treats and prevents diaphragm fatigue.
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Affiliation(s)
- Janet D Pierce
- School of Nursing, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
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38
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Ozias MK, Carlson SE, Levant B. Maternal parity and diet (n-3) polyunsaturated fatty acid concentration influence accretion of brain phospholipid docosahexaenoic acid in developing rats. J Nutr 2007; 137:125-9. [PMID: 17182812 DOI: 10.1093/jn/137.1.125] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The long-chain PUFA, docosahexaenoic acid [22:6(n-3), DHA], a major component of neuronal membrane phospholipids, accumulates in brain during late prenatal and early neonatal development and is essential for optimal attentional and cognitive function. Because all nutrition is supplied to the developing fetus/neonate by the mother and maternal DHA status is affected by parity, this study examined the effects of maternal diet and parity on DHA accretion in the developing brain. Whole brain total phospholipid fatty acid composition was determined by TLC and GC in weanling male Long-Evans rats (n = 5) from the 1st, 2nd, 3rd, or 4th litters of dams fed diets containing alpha-linolenic acid (ALA), containing ALA and preformed DHA (ALA + DHA), or lacking ALA (low-ALA). First-litter low-ALA offspring exhibited a decrease in phospholipid fatty acid DHA content to 68% of 1st-litter ALA pups. DHA in 2nd-litter low-ALA pups was further decreased to 55% of 1st-litter ALA pups, but further decreases were not observed in subsequent litters. DHA levels increased 15-20% in 2nd to 4th-litter ALA + DHA pups and 11% in 4th-litter ALA pups compared with 1st-litter ALA pups. These findings demonstrate that maternal diet and parity interact to affect offspring brain DHA status and suggest that maternal multiparity may place offspring at greater risk of decreased accretion of brain DHA if the maternal diet contains insufficient (n-3) PUFA.
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Affiliation(s)
- Marlies K Ozias
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160, USA
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39
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Levant B, Ozias MK, Carlson SE. Specific brain regions of female rats are differentially depleted of docosahexaenoic acid by reproductive activity and an (n-3) fatty acid-deficient diet. J Nutr 2007; 137:130-4. [PMID: 17182813 DOI: 10.1093/jn/137.1.130] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Low tissue levels of (n-3) PUFA, particularly docosahexaenoic acid [DHA, 22:6(n-3)], are implicated in postpartum depression. Brain DHA content is depleted in female rats undergoing pregnancy and lactation when the diet supplies inadequate (n-3) PUFA. In this study, the effects of DHA depletion as a result of reproductive activity and an (n-3) PUFA-deficient diet were examined in 8 specific brain regions of female rats after undergoing 2 sequential reproductive cycles. Virgin females, fed the alpha-linolenic acid (ALA)-containing or deficient (low-ALA) diets for a commensurate duration (13 wk) served as a control for reproduction. Total phospholipid composition of each brain region was determined at weaning (postnatal d 21) by TLC/GC. The regional PUFA composition of ALA virgins was similar to that previously measured in male rats. All brain regions examined were affected by reproductive activity and/or the low-ALA diet; however, the magnitude of the loss of DHA and compensatory incorporation of docosapentaenoic acid [(n-6) DPA, 22:5(n-6)] varied among brain regions. In low-ALA parous dams, frontal cortex (77% of ALA virgin) and temporal lobe (83% of ALA virgin), regions involved in cognition and affect, were among those exhibiting the greatest depletion of DHA. Caudate-putamen also exhibited significant depletion of DHA (82% of ALA virgin), whereas only (n-6) DPA levels were altered in ventral striatum, hypothalamus, hippocampus, and cerebellum. This pattern of changes in regional DHA and (n-6) DPA content suggests that specific neuronal systems may be differentially affected by depletion of brain DHA in the postpartum organism.
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Affiliation(s)
- Beth Levant
- Departments of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160, USA.
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40
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Levant B, Ozias MK, Jones KA, Carlson SE. Differential effects of modulation of docosahexaenoic acid content during development in specific regions of rat brain. Lipids 2006; 41:407-14. [PMID: 16933785 DOI: 10.1007/s11745-006-5114-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Variation in brain FA composition, particularly decreased DHA (22:6n-3), affects neurodevelopment, altering visual, attentional, and cognitive functions, and is implicated in several neuropsychiatric disorders. To further understand how specific brain processes and systems are affected by variation in brain DHA content, we sought to determine whether specific brain regions were differentially affected by treatments that alter brain DHA content. Adult male Long-Evans rats were raised from conception using diet/breeding treatments to produce four groups with distinct brain phospholipid compositions. Total phospholipid FA composition was determined in whole brain and 15 brain regions by TLC/GC. Brain regions exhibited significantly different DHA contents, with the highest levels observed in the frontal cortex and the lowest in the substantia nigra/ventral tegmental area. Increased availability of DHA resulted in increased DHA content only in the olfactory bulb, parietal cortex, and substantia nigra/ventral tegmental area. In contrast, treatment that decreased whole-brain DHA levels decreased DHA content in all brain regions except the thalamus, dorsal midbrain, and the substantia nigra/ventral tegmental area. Alterations in DHA level were accompanied by changes in docosapentaenoic acid (n-6 DPA, 22:5n-6) content; however, the change in DHA and n-6 DPA was nonreciprocal in some brain regions. These findings demonstrate that the FA compositions of specific brain regions are differentially affected by variation in DHA availability during development. These differential effects may contribute to the specific neurochemical and behavioral effects observed in animals with variation in brain DHA content.
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Affiliation(s)
- Beth Levant
- Department of Pharmacology, University of Kansas Medical Center, Kansas City, Kansas 66160, USA.
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41
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Levant B, Radel JD, Carlson SE. Reduced brain DHA content after a single reproductive cycle in female rats fed a diet deficient in N-3 polyunsaturated fatty acids. Biol Psychiatry 2006; 60:987-90. [PMID: 16499882 DOI: 10.1016/j.biopsych.2005.12.013] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2005] [Revised: 11/29/2005] [Accepted: 12/15/2005] [Indexed: 11/30/2022]
Abstract
BACKGROUND Low levels of n-3 polyunsaturated fatty acids (PUFAs), particularly docosahexaenoic acid (DHA, 22:6n3), are implicated in postpartum depression. METHODS The effects of pregnancy and lactation on brain phospholipid fatty acid content were determined in female rats fed diets containing sufficient (control) or negligible (deficient) alpha-linolenic acid (18:3n-3), the dietary precursor of DHA, beginning at conception. Female virgins, fed the diets for 6 weeks, served as control animals. Whole brain total phospholipid composition was determined at weaning by GC. RESULTS Brain DHA content of postpartum dams fed the deficient diet was decreased by 21% compared with age-matched virgin control animals, with a reciprocal increase in docosapentaenoic acid (22:5n6) to 243%. CONCLUSIONS Under dietary conditions supplying inadequate n-3 PUFAs, maternal brain DHA content can be reduced after a single reproductive cycle. This depletion may affect neuronal function and thus the sensitivity of the postpartum organism to stress.
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Affiliation(s)
- Beth Levant
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160, USA.
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Levant B, Ozias MK, Carlson SE. Sex-specific effects of brain LC-PUFA composition on locomotor activity in rats. Physiol Behav 2006; 89:196-204. [PMID: 16875705 DOI: 10.1016/j.physbeh.2006.06.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2006] [Revised: 05/18/2006] [Accepted: 06/08/2006] [Indexed: 01/01/2023]
Abstract
Insufficient availability of n-3 polyunsaturated fatty acids (PUFAs) during pre- and neonatal development decreases accretion of docosahexaenoic acid (DHA, 22:6n-3) in the developing brain and is associated with sub-optimal sensory and cognitive function in humans, altered behavior in animals, and may contribute to neurodevelopmental disorders such as attention deficit hyperactivity disorder and schizophrenia. This study examined the effects of variation in dietary availability of n-3 PUFAs on brain fatty acid composition and the consequent effects on locomotor activity in male and female Long-Evans rats. Rats were raised from conception using purified diets and breeding protocols designed to produce four groups with distinct brain phospholipid compositions varying in DHA content and/or the proportion of n-3 and n-6 PUFAs. Locomotor behavior was measured for a 2-h period on postnatal days 28, 42, 56, and 70. In males, decreased brain DHA produced alterations in activity that were most pronounced post-adolescence and with the greatest decrease in DHA. However, the behavioral effects in males were not linearly related to brain DHA level. In contrast, no significant effects of variation in brain fatty acid composition were observed in females. This suggests that variation in brain DHA content produces sex-specific alterations in locomotor activity and that the neurochemical alterations underlying the observed behavioral changes vary depending on the degree of DHA depletion.
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Affiliation(s)
- Beth Levant
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 USA.
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McNamara RK, Levant B, Taylor B, Ahlbrand R, Liu Y, Sullivan JR, Stanford K, Richtand NM. C57BL/6J mice exhibit reduced dopamine D3 receptor-mediated locomotor-inhibitory function relative to DBA/2J mice. Neuroscience 2006; 143:141-53. [PMID: 16938406 PMCID: PMC1815378 DOI: 10.1016/j.neuroscience.2006.07.015] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2005] [Revised: 06/19/2006] [Accepted: 07/18/2006] [Indexed: 01/23/2023]
Abstract
Previous reports have identified greater sensitivity to the locomotor-stimulating, sensitizing, and reinforcing effects of amphetamine in inbred C57BL/6J mice relative to inbred DBA/2J mice. The dopamine D3 receptor (D3R) plays an inhibitory role in the regulation of rodent locomotor activity, and exerts inhibitory opposition to D1 receptor (D1R)-mediated signaling. Based on these observations, we investigated D3R expression and D3R-mediated locomotor-inhibitory function, as well as D1R binding and D1R-mediated locomotor-stimulating function, in C57BL/6J and DBA/2J mice. C57BL/6J mice exhibited lower D3R binding density (-32%) in the ventral striatum (nucleus accumbens/islands of Calleja), lower D3R mRNA expression (-26%) in the substantia nigra/ventral tegmentum, and greater D3R mRNA expression (+40%) in the hippocampus, relative to DBA/2J mice. There were no strain differences in DR3 mRNA expression in the ventral striatum or prefrontal cortex, nor were there differences in D1R binding in the ventral striatum. Behaviorally, C57BL/6J mice were less sensitive to the locomotor-inhibitory effect of the D3R agonist PD128907 (10 microg/kg), and more sensitive to the locomotor-stimulating effects of novelty, amphetamine (1 mg/kg), and the D1R-like agonist +/- -1-phenyl-2,3,4,5-tetrahydro-(1H)-3-benzazepine-7,8,-diol hydrochloride (SKF38393) (5-20 mg/kg) than DBA/2J mice. While the selective D3R antagonist N-(4-[4-{2,3-dichlorphenyl}-1 piperazinyl]butyl)-2-fluorenylcarboxamide (NGB 2904) (0.01-1.0 mg/kg) augmented novelty-, amphetamine-, and SKF38393-induced locomotor activity in DBA/2J mice, it reduced novelty-induced locomotor activity in C57BL/6J mice. Collectively, these results demonstrate that C57BL/6J mice exhibit less D3R-mediated inhibitory function relative to DBA/2J mice, and suggest that reduced D3R-mediated inhibitory function may contribute to heightened sensitivity to the locomotor-stimulating effects of amphetamine in the C57BL/6J mouse strain. Furthermore, these data demonstrate that comparisons between C57BL/6J and DBA/2J mouse strains provide a model for elucidating the molecular determinants of genetic influence on D3R function.
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MESH Headings
- 2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine/pharmacology
- Analysis of Variance
- Animals
- Behavior, Animal/drug effects
- Behavior, Animal/physiology
- Benzazepines/pharmacology
- Benzopyrans/pharmacology
- Dopamine Agonists/pharmacology
- Dopamine Antagonists/pharmacology
- Dose-Response Relationship, Drug
- Exploratory Behavior/physiology
- Fluorenes/pharmacology
- Gene Expression/physiology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Inbred DBA
- Motor Activity/drug effects
- Motor Activity/physiology
- Oxazines/pharmacology
- Piperazines/pharmacology
- Protein Binding/drug effects
- Protein Binding/physiology
- RNA, Messenger/metabolism
- Receptors, Dopamine D3/antagonists & inhibitors
- Receptors, Dopamine D3/physiology
- Species Specificity
- Tritium/pharmacokinetics
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Affiliation(s)
- R K McNamara
- Department of Psychiatry, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0559, USA.
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Levant B, Ozias MK, Carlson SE. Diet (n-3) polyunsaturated fatty acid content and parity interact to alter maternal rat brain phospholipid fatty acid composition. J Nutr 2006; 136:2236-42. [PMID: 16857847 DOI: 10.1093/jn/136.8.2236] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Low tissue levels of (n-3) polyunsaturated fatty acids (PUFAs), particularly docosahexaenoic acid [DHA, 22:6(n-3)], are implicated in postpartum depression. The effects of 1-4 sequential reproductive cycles on maternal brain phospholipid fatty acid composition were determined in female rats fed diets containing alpha-linolenic acid (ALA), containing ALA and pre-formed DHA (ALA+DHA), or lacking ALA (low-ALA). Virgin females, fed the diets for commensurate durations served as a control for reproduction. Whole-brain total phospholipid composition was determined at weaning by TLC/GC. A single reproductive cycle on the low-ALA diet decreased brain DHA content by 18% compared to ALA primiparas (P < 0.05), accompanied by incorporation of docosapentaenoic acid ((n-6) DPA, 22:5(n-6)) to 280% of ALA primiparas (P < 0.05). DHA was not further decreased after subsequent cycles; however, there was an additional increase in (n-6) DPA after the second cycle (P < 0.05). Brain DHA of virgin females fed the low-ALA diet for 27 wk decreased 15% (P < 0.05), but was accompanied by a more modest increase in (n-6) DPA than in parous low-ALA dams (P < 0.05). Virgin females and parous dams fed the diet containing ALA+DHA exhibited only minor changes in brain fatty acid composition. These observations demonstrate that brain DHA content of adult animals is vulnerable to depletion under dietary conditions that supply inadequate (n-3) PUFAs, that this effect is augmented by the physiological demands of pregnancy and lactation, and that maternal diet and parity interact to affect maternal brain PUFA status.
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Affiliation(s)
- Beth Levant
- The Smith Mental Retardation Research Center, University of Kansas Medical Center, Kansas City, KS 66160, USA.
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Chen J, Ding K, Levant B, Wang S. Corrigendum to “Design of novel hexahydropyrazinoquinolines as potent and selective dopamine D3 receptor ligands with improved solubility”. Bioorg Med Chem Lett 2006. [DOI: 10.1016/j.bmcl.2006.04.083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Levant B, Crane JF, Carlson SE. Sub-chronic antipsychotic drug treatment does not alter brain phospholipid fatty acid composition in rats. Prog Neuropsychopharmacol Biol Psychiatry 2006; 30:728-32. [PMID: 16442197 DOI: 10.1016/j.pnpbp.2005.11.034] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/30/2005] [Indexed: 11/19/2022]
Abstract
Altered membrane phospholipid fatty acid composition is reported in schizophrenia and appears to be reduced by antipsychotic drug treatment. To determine whether antipsychotic drugs have a direct effect on brain phospholipid fatty acid composition, the effects of sub-chronic treatment with a "typical" and an "atypical" antipsychotic drug were determined in adult male Sprague-Dawley rats. Rats were treated with haloperidol (1 mg/kg), clozapine (20 mg/kg) or vehicle daily for 21 days. Whole brain total phospholipid composition was determined by gas chromatography. No alterations in brain phospholipid composition were produced by either drug. This suggests that the apparent normalization of membrane phospholipids observed in drug-treated schizophrenic patients is not due to a direct pharmacological effect of these drugs nor can the pharmacological effects of these drugs occurring in this time frame be attributed to alterations in neuronal membrane fatty acid composition.
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Affiliation(s)
- Beth Levant
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA.
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Richards TL, Pazdernik TL, Levant B. Clorgyline‐induced modification of sensitization to quinpirole: effects on behavior and local cerebral glucose utilization. FASEB J 2006. [DOI: 10.1096/fasebj.20.4.a684-c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Toni L Richards
- PharmacolUniv Kansas Med Ctr3901 Rainbow BlvdKansas CityKS66160
| | | | - Beth Levant
- PharmacolUniv Kansas Med Ctr3901 Rainbow BlvdKansas CityKS66160
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Chen J, Ding K, Levant B, Wang S. Design of novel hexahydropyrazinoquinolines as potent and selective dopamine D3 receptor ligands with improved solubility. Bioorg Med Chem Lett 2006; 16:443-6. [PMID: 16290142 DOI: 10.1016/j.bmcl.2005.09.053] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2005] [Revised: 09/07/2005] [Accepted: 09/08/2005] [Indexed: 11/20/2022]
Abstract
We have recently reported hexahydropyrazinoquinolines as a new class of dopamine 3 (D(3)) receptor ligands with high-affinity to the D(3) receptor and excellent selectivity over the closely related D(1)-like and D(2)-like receptors. However, our previously reported most potent and selective D(3) ligands have poor aqueous solubility, which greatly hinders our in vivo studies aimed at evaluation of their therapeutic potential in animal models. In this study, we wish to report the design, synthesis, and evaluation of a series of new hexahydropyrazinoquinolines as D(3) ligands with improved solubility. Among them, compound 4g has a K(i) value of 9.7 nM for the D(3) receptor and displays a selectivity of >5000 and 466 times over the D(1)-like and D(2)-like receptors, respectively. Importantly, the hydrochloride salt form of compound 4g has a good aqueous solubility (>50 mg/mL) and represents a promising D(3) ligand for further in vivo evaluations of its therapeutic potential for the treatment of drug abuse, restless legs syndrome, schizophrenia, Parkinson's disease, and depression.
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Affiliation(s)
- Jianyong Chen
- Departments of Internal Medicine and Medicinal Chemistry, University of Michigan, 1500 East Medical Center Drive, Ann Arbor, MI 48109-0934, USA
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Ding K, Chen J, Ji M, Wu X, Varady J, Yang CY, Lu Y, Deschamps JR, Levant B, Wang S. Enantiomerically Pure Hexahydropyrazinoquinolines as Potent and Selective Dopamine 3 Subtype Receptor Ligands. J Med Chem 2005; 48:3171-81. [PMID: 15857123 DOI: 10.1021/jm049031l] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report the design and synthesis of a series of enantiomerically pure hexahydropyrazinoquinolines as potent and selective ligands for the dopamine 3 subtype receptor using a newly developed synthetic method and using in vitro pharmacological evaluation. Our efforts yielded optically pure ligands with high affinities for the D(3) receptor and outstanding selectivity over closely related D(1)-like and D(2)-like receptors. For example, compound 38a has a K(i) value of 5.7 nM to the D(3) receptor and selectivity greater than 10000- and 1600-fold over the D(1)-like and D(2)-like receptors, respectively, and thus is one of the most selective D(3) ligands reported to date.
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Affiliation(s)
- Ke Ding
- Department of Internal Medicine and Medicinal Chemistry, University of Michigan, 1500 East Medical Center Drive, Ann Arbor, Michigan 48109-0934, USA
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Richards TL, Pazdernik TL, Levant B. Altered quinpirole-induced local cerebral glucose utilization in anterior cortical regions in rats after sensitization to quinpirole. Brain Res 2005; 1042:53-61. [PMID: 15823253 DOI: 10.1016/j.brainres.2005.02.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2004] [Revised: 02/02/2005] [Accepted: 02/04/2005] [Indexed: 11/30/2022]
Abstract
Dopaminergic psychostimulants produce behavioral responses of greater magnitude with repeated, intermittent administration, than a single, acute dose, a phenomenon known as "sensitization." Most studies of sensitization have focused on the "motive circuit"; however, some additional anterior cortical regions also appear to be affected. In this study, alterations in regional neuronal activity in anterior cortical brain areas produced by quinpirole, a D(2)/D(3) agonist, were assessed on the basis of local cerebral glucose utilization (LCGU) using the [(14)C]-2-deoxyglucose (2-DG) method. Adult, male Long-Evans rats (180-200 g, n = 7-9/group) were subjected to ten injections of quinpirole (0.5 mg/kg, s.c.) administered every third day; controls and drug-naive rats received saline. Locomotor activity was quantitated after injections one and ten to confirm sensitization. The 2-DG procedure was initiated 60 min after an 11th injection in freely moving rats. LCGU was determined in 11 anterior cortical brain regions by quantitative autoradiography. In drug-naive rats, quinpirole decreased LCGU in the cingulate cortex-area 3 (-16%) and infralimbic cortex (-16%). In sensitized rats, quinpirole decreased LCGU in the cingulate cortex-area 1 (-19%), frontal cortex-area 3 (-19%), lateral orbital cortex (-18%), medial/ventral orbital cortex (-17%), and parietal cortex (-17%) as well as in the cingulate cortex-area 3 (-19%) and infralimbic cortex (-20%); (all P < 0.05 v. control). This suggests that decreased neuronal activity in the cingulate cortex-area 1, frontal cortex-area 3, lateral orbital cortex, medial/ventral orbital cortex, and parietal cortex, in addition to altered activity in the motive circuit, may underlie the augmented behavioral response to quinpirole in sensitized animals.
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Affiliation(s)
- Toni L Richards
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160-7417, USA
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