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Natarajan R, Harding JW, Wright JW. A role for matrix metalloproteinases in nicotine-induced conditioned place preference and relapse in adolescent female rats. J Exp Neurosci 2013; 7:1-14. [PMID: 25157203 PMCID: PMC4089657 DOI: 10.4137/jen.s11381] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Reconfiguration of extracellular matrix proteins appears to be necessary for the synaptic plasticity that underlies memory consolidation. The primary candidates involved in controlling this process are a family of endopeptidases called matrix metalloproteinases (MMPs); however, the potential role of MMPs in nicotine addiction-related memories has not been adequately tested. Present results indicate transient changes in hippocampal MMP-2, -3, and -9 expression following context dependent learning of nicotine-induced conditioned place preference (CPP). Members of a CPP procedural control group also indicated similar MMP changes, suggesting that memory activation occurred in these animals as well. However, hippocampal MMP-9 expression was differentially elevated in members of the nicotine-induced CPP group on days 4 and 5 of training. Inhibition of MMPs using a broad spectrum MMP inhibitor (FN439) during nicotine-induced CPP training blocked the acquisition of CPP. Elevations in hippocampal and prefrontal cortex MMP-3 expression-but not MMP-2 and -9-accompanied reactivation of a previously learned drug related memory. Decreases in the actin regulatory cytoskeletal protein cortactin were measured in the HIP and PFC during the initial two days of acquisition of CPP; however, no changes were seen following re-exposure to the drug related environment. These results suggest that MMP-9 may be involved in facilitating the intracellular and extracellular events required for the synaptic plasticity underlying the acquisition of nicotine-induced CPP. Furthermore, MMP-3 appears to be important during re-exposure to the drug associated environment. However, rats introduced into the CPP apparatus and given injections of vehicle rather than nicotine during training also revealed a pattern of MMP expression similar to nicotine-induced CPP animals.
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Affiliation(s)
- Reka Natarajan
- Department of Neurosciences, University of Toledo College of Medicine, Toledo, OH, USA
| | - Joseph W Harding
- Departments of Psychology, and Veterinary and Comparative Anatomy, Pharmacology, and Physiology, Washington State University, Pullman, WA, USA
| | - John W Wright
- Departments of Psychology, and Veterinary and Comparative Anatomy, Pharmacology, and Physiology, Washington State University, Pullman, WA, USA
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Lazartigues E, Sinnayah P, Augoyard G, Gharib C, Johnson AK, Davisson RL. Enhanced water and salt intake in transgenic mice with brain-restricted overexpression of angiotensin (AT1) receptors. Am J Physiol Regul Integr Comp Physiol 2008; 295:R1539-45. [PMID: 18753266 DOI: 10.1152/ajpregu.00751.2007] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To address the relative contribution of central and peripheral angiotensin II (ANG II) type 1A receptors (AT(1A)) to blood pressure and volume homeostasis, we generated a transgenic mouse model [neuron-specific enolase (NSE)-AT(1A)] with brain-restricted overexpression of AT(1A) receptors. These mice are normotensive at baseline but have dramatically enhanced pressor and bradycardic responses to intracerebroventricular ANG II or activation of endogenous ANG II production. Here our goal was to examine the water and sodium intake in this model under basal conditions and in response to increased ANG II levels. Baseline water and NaCl (0.3 M) intakes were significantly elevated in NSE-AT(1A) compared with nontransgenic littermates, and bolus intracerebroventricular injections of ANG II (200 ng in 200 nl) caused further enhanced water intake in NSE-AT(1A). Activation of endogenous ANG II production by sodium depletion (10 days low-sodium diet followed by furosemide, 1 mg sc) enhanced NaCl intake in NSE-AT(1A) mice compared with wild types. Fos immunohistochemistry, used to assess neuronal activation, demonstrated sodium depletion-enhanced activity in the anteroventral third ventricle region of the brain in NSE-AT(1A) mice compared with control animals. The results show that brain-selective overexpression of AT(1A) receptors results in enhanced salt appetite and altered water intake. This model provides a new tool for studying the mechanisms of brain AT(1A)-dependent water and salt consumption.
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Affiliation(s)
- Eric Lazartigues
- Department of Anatomy and Cell Biology, The University of Iowa, Iowa City, Iowa, USA
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3
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McLay RN, Pan W, Kastin AJ. Effects of peptides on animal and human behavior: a review of studies published in the first twenty years of the journal Peptides. Peptides 2001; 22:2181-255. [PMID: 11786208 DOI: 10.1016/s0196-9781(01)00550-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This review catalogs effects of peptides on various aspects of animal and human behavior as published in the journal Peptides in its first twenty years. Topics covered include: activity levels, addiction behavior, ingestive behaviors, learning and memory-based behaviors, nociceptive behaviors, social and sexual behavior, and stereotyped and other behaviors. There are separate tables for these behaviors and a short introduction for each section.
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Affiliation(s)
- R N McLay
- Naval Medical Center San Diego, Department of Psychiatry, San Diego, CA, USA
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4
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Johnson WE, Propper CR. Effects of dehydration on plasma osmolality, thirst-related behavior, and plasma and brain angiotensin concentrations in Couch's spadefoot toad, Scaphiopus couchii. THE JOURNAL OF EXPERIMENTAL ZOOLOGY 2000; 286:572-84. [PMID: 10766966 DOI: 10.1002/(sici)1097-010x(20000501)286:6<572::aid-jez4>3.0.co;2-b] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Under dehydrating conditions, many terrestrial vertebrates species exhibit increases in plasma osmolality and their drinking behavior. Under some circumstances, this behavioral change is accompanied by changes in plasma and central angiotensin concentrations, and it has been proposed that these changes in angiotensin levels induce the thirst-related behaviors. In response to dehydration, the spadefoot toad, Scaphiopus couchii, exhibits thirst-related behavior in the form of cutaneous drinking. This behavior has been termed water absorption response (WR) behavior. Spadefoot toads live in harsh desert environments and are subject annually to dehydrating conditions that may induce thirst-related behavior. We tested the hypothesis that an increase in WR behavior is associated with both an increase in plasma osmolality and an increase in plasma and brain angiotensin concentrations. First, we determined the degree of dehydration that was necessary to initiate WR behavior. Animals dehydrated to 85% of their standard bladder-empty weight via deprivation of water exhibited WR behavior more frequently than control toads left in home containers with water available. Next, using the same dehydration methods, we determined the plasma osmolality and sodium concentrations of dehydrated toads. Toads dehydrated to 85% standard weight also had a significant increase in plasma osmolality, but exhibited no overall change in plasma sodium concentrations, indicating that while an overall increase in plasma osmolality appears to be associated with WR behavior in S. couchii, changes in sodium concentrations alone are not sufficient to induce the behavior. Finally, plasma and brain angiotensin concentrations were measured in control toads and toads dehydrated to 85% standard weight. Plasma and brain angiotensin concentrations did not increase in dehydrated toads, indicating that dehydration-induced WR behavior that is associated with changes in plasma osmolality may not be induced by changes in endogenous angiotensin concentrations in S. couchii.
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Affiliation(s)
- W E Johnson
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona 86011, USA.
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Mayer LP, Propper CR. Intra- and extracellular dehydration has no effect on plasma levels of angiotensin II in an amphibian. THE JOURNAL OF EXPERIMENTAL ZOOLOGY 2000; 286:343-9. [PMID: 10684557 DOI: 10.1002/(sici)1097-010x(20000301)286:4<343::aid-jez2>3.0.co;2-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Previous studies have demonstrated that both dehydration (intra and extracellular) and treatment with angiotensin II (A-II) induce changes in thirst-related behavior in the spadefoot toad, Scaphiopus couchii. One of the steps in determining a causal relationship between a hormone and a behavior is to determine that there is association between an animal's performance of the behavior and changes in endogenous hormonal concentrations. The hypothesis tested that plasma levels of the peptide hormone A-II would change as a result of dehydration known to induce water absorption response (WR) behavior in the spadefoot toad. Plasma samples were taken from toads dehydrated intracellularly by injection of hypertonic solutions of NaCl or sucrose at levels known to induce WR behavior. As an osmotic control, a group of animals was injected with urea, which has been demonstrated to not induce WR behavior. In order to determine the effects of extracellular dehydration on plasma, A-II levels in toads dehydrated by plasma volume depletion via cardiac puncture were compared to sham-punctured controls. None of the treatments in any experiment resulted in significant differences in plasma levels of angiotensin II among groups sampled at the time when WR behavior occurs. These results do not support the hypothesis that dehydration-induced thirst is stimulated by changes in plasma A-II concentrations at the onset of WR behavior. J. Exp. Zool. 286:343-349, 2000.
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Affiliation(s)
- L P Mayer
- Northern Arizona University, Department of Biological Sciences, Flagstaff, Arizona 86001, USA.
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Barney CC, Smith GL, Folkerts MM. Thermal dehydration-induced thirst in spontaneously hypertensive rats. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 276:R1302-10. [PMID: 10233020 DOI: 10.1152/ajpregu.1999.276.5.r1302] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Spontaneously hypertensive (SH) rats and normotensive Wistar-Kyoto (WKY) rats were exposed to either 25 or 37.5 degrees C for 3.5 h, and their thermal and water balance responses were compared. After exposure, either a blood sample was obtained or the rats were allowed to rehydrate for 4 h. SH rats had both higher core temperatures and evaporative water losses during heat exposure. Measurements of hematocrit, hemoglobin concentration, plasma protein and sodium concentrations, and plasma osmolality indirectly showed that the SH rats were dehydrated relative to the WKY rats after exposure to either 25 or 37.5 degrees C. SH rats drank significantly more water but also had significantly higher urine volumes than the WKY rats and thus rehydrated only slightly better than the WKY rats. SH and WKY rats had similar levels of water intake and urine output after 24 h of water deprivation. The elevated thermal response of SH rats to heat exposure does not appear to lead to uncompensatable changes in body water status.
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Affiliation(s)
- C C Barney
- Department of Biology, Hope College, Holland, Michigan 49423, USA.
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Abstract
Angiotensin (ANG) II is a powerful and phylogenetically widespread stimulus to thirst and sodium appetite. When it is injected directly into sensitive areas of the brain, it causes an immediate increase in water intake followed by a slower increase in NaCl intake. Drinking is vigorous, highly motivated, and rapidly completed. The amounts of water taken within 15 min or so of injection can exceed what the animal would spontaneously drink in the course of its normal activities over 24 h. The increase in NaCl intake is slower in onset, more persistent, and affected by experience. Increases in circulating ANG II have similar effects on drinking, although these may be partly obscured by accompanying rises in blood pressure. The circumventricular organs, median preoptic nucleus, and tissue surrounding the anteroventral third ventricle in the lamina terminalis (AV3V region) provide the neuroanatomic focus for thirst, sodium appetite, and cardiovascular control, making extensive connections with the hypothalamus, limbic system, and brain stem. The AV3V region is well provided with angiotensinergic nerve endings and angiotensin AT1 receptors, the receptor type responsible for acute responses to ANG II, and it responds vigorously to the dipsogenic action of ANG II. The nucleus tractus solitarius and other structures in the brain stem form part of a negative-feedback system for blood volume control, responding to baroreceptor and volume receptor information from the circulation and sending ascending noradrenergic and other projections to the AV3V region. The subfornical organ, organum vasculosum of the lamina terminalis and area postrema contain ANG II-sensitive receptors that allow circulating ANG II to interact with central nervous structures involved in hypovolemic thirst and sodium appetite and blood pressure control. Angiotensin peptides generated inside the blood-brain barrier may act as conventional neurotransmitters or, in view of the many instances of anatomic separation between sites of production and receptors, they may act as paracrine agents at a distance from their point of release. An attractive speculation is that some are responsible for long-term changes in neuronal organization, especially of sodium appetite. Anatomic mismatches between sites of production and receptors are less evident in limbic and brain stem structures responsible for body fluid homeostasis and blood pressure control. Limbic structures are rich in other neuroactive peptides, some of which have powerful effects on drinking, and they and many of the classical nonpeptide neurotransmitters may interact with ANG II to augment or inhibit drinking behavior. Because ANG II immunoreactivity and binding are so widely distributed in the central nervous system, brain ANG II is unlikely to have a role as circumscribed as that of circulating ANG II. Angiotensin peptides generated from brain precursors may also be involved in functions that have little immediate effect on body fluid homeostasis and blood pressure control, such as cell differentiation, regeneration and remodeling, or learning and memory. Analysis of the mechanisms of increased drinking caused by drugs and experimental procedures that activate the renal renin-angiotensin system, and clinical conditions in which renal renin secretion is increased, have provided evidence that endogenously released renal renin can generate enough circulating ANG II to stimulate drinking. But it is also certain that other mechanisms of thirst and sodium appetite still operate when the effects of circulating ANG II are blocked or absent, although it is not known whether this is also true for angiotensin peptides formed in the brain. Whether ANG II should be regarded primarily as a hormone released in hypovolemia helping to defend the blood volume, a neurotransmitter or paracrine agent with a privileged role in the neural pathways for thirst and sodium appetite of all kinds, a neural organizer especially in sodium appetit
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Wright JW, Bechtholt AJ, Chambers SL, Harding JW. Angiotensin III and IV activation of the brain AT1 receptor subtype in cardiovascular function. Peptides 1996; 17:1365-71. [PMID: 8971933 DOI: 10.1016/s0196-9781(96)00226-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The present investigation determined that native angiotensins II and III (ANG II and III) were equipotent as pressor agents when ICV infused in alert rats, whereas native angiotensin IV (ANG IV) was less potent. An analogue of each of these angiotensins was prepared with a hydroxyethylamine (HEA) amide bond replacement at the N-terminus, yielding additional resistance to degradation. These three angiotensin analogues, HEA-ANG II, HEA-ANG III, and HEA-ANG IV, were equivalent with respect to maximum elevation in pressor responses when ICV infused; and each evidenced significantly extended durations of effect compared with their respective native angiotensin. Comparing analogues, HEA-ANG II had a significantly longer effect compared with HEA-ANG III, and HEA-ANG IV, whereas the latter were equivalent. Pretreatment with the AT1 receptor subtype antagonist, Losartan (DuP753), blocked subsequent pressor responses to each of these analogues, suggesting that these responses were mediated by the AT1 receptor subtype. Pretreatment with the specific AT4 receptor subtype antagonist, Divalinal (HED 1291), failed to influence pressor responses induced by the subsequent infusion of these analogues. These results suggest an important role for Ang III, and perhaps ANG IV, in brain angiotensin pressor responses mediated by the AT1 receptor subtype.
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Affiliation(s)
- J W Wright
- Department of Psychology, Washington State University, Pullman 99164-4820, USA
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Batt CM, Jensen LL, Harding JW, Wright JW. Microinfusion of aminopeptidase M into the paraventricular nucleus of the hypothalamus in normotensive and hypertensive rats. Brain Res Bull 1996; 39:235-40. [PMID: 8963689 DOI: 10.1016/0361-9230(95)02141-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR) received aminopeptidase M (AmM) delivered into the paraventricular nucleus of the hypothalamus (PVN). Resulting changes in blood pressure were recorded in both anesthetized and alert animals. The findings indicate significant dose-determined decreases in blood pressure in members of both strains with SHR more responsive than WKY rats. The respective drops in blood pressure for members within each strain were equivalent for the anesthetized and alert conditions. Pretreatment with the specific angiotensin receptor antagonist, sarthran, [Sar1, Thr2] Angll, into the PVN greatly diminished these responses, suggesting the involvement of the brain angiotensin system. Additionally, a sympathetic nervous system blocker, hexamethonium, and the arginine vasopressin antagonist, Pmp1, O-Me-Tyr2-[Arg] vasopressin, were peripherally administered to assess the potential contributions of these systems to cardiovascular regulation by the brain angiotensin system. The use of these blockers, individually and combined, attenuated responsiveness to infusion of AmM into the PVN. We conclude that AmM can act as a hypotensive agent in both SHR and WKY rats, and that this decrease in blood pressure is at least partially mediated via the brain angiotensin system although other systems may play a role.
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Affiliation(s)
- C M Batt
- Department of Social and Behavioral Sciences, Sacred Heart University, Fairfield, CT 06432-1000, USA
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Wright JW, Harding JW. Brain angiotensin receptor subtypes AT1, AT2, and AT4 and their functions. REGULATORY PEPTIDES 1995; 59:269-95. [PMID: 8577933 DOI: 10.1016/0167-0115(95)00084-o] [Citation(s) in RCA: 128] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- J W Wright
- Department of Psychology, Washington State University, Pullman 99164-4820, USA
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Braszko JJ, Kułakowska A, Wiśniewski K. Angiotensin II and its 3-7 fragment improve recognition but not spatial memory in rats. Brain Res Bull 1995; 37:627-31. [PMID: 7670888 DOI: 10.1016/0361-9230(95)00056-k] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The effects of angiotensin II (AII), its 3-7 fragment [AII(3-7)] and the substituted 3-7 fragment [Leu-5,AII(3-7)] given intracerebroventricularly (ICV) at the dose of 1 nmole each, on spatial memory and recognition were tested. AII(3-7) increased while Leu-5,AII(3-7) slightly decreased session to session foot shock reinforced runtime to the goal in a complex 6 chamber maze. The animals treated with AII performed in the maze similarly to saline injected controls. Overall number of errors was unchanged in all peptide treated groups in comparison with the control group. Object recognition was significantly improved in all the peptide treated groups except for the Leu-5,AII(3-7) group. The results point to the facilitation of recognition and lack of influence on, or even attenuation of, spatial memory by AII and its 3-7 fragment. Leu-5,AII(3-7) caused similar though less pronounced effects.
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Affiliation(s)
- J J Braszko
- Department of Pharmacology, Białlystok Medical Academy, Poland
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Wright JW, Hamilton TA, Harding JW. Anomalous effects of losartan on aminopeptidase-induced reductions of blood pressure in SHR. Brain Res Bull 1995; 36:169-74. [PMID: 7895095 DOI: 10.1016/0361-9230(94)00186-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The present investigation initially determined that a commercially available aminopeptidase M (AmM, Sigma Chemical) can lower blood pressure when intracerebroventricularly (ICV) infused in spontaneously hypertensive rats (SHR). Pretreatment with the angiotensin II (AngII) receptor subtype 1 (AT1) antagonist, DuP 753 (losartan) significantly attenuated this hypotensive effect, in a dose-dependent manner, while pretreatment with the AngII receptor subtype 2 (AT2) antagonist, PD123177, did not influence AmM-induced hypotension. These results suggest that AT1 receptors may be involved in the hypotension accompanying the ICV infusion of AmM; however, the relationship among available AT1 sites, angiotensin ligands, and peptidase activity appears to be complicated with the likely involvement of additional, as yet unspecified, brain peptide systems possessing cardiovascular action.
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Affiliation(s)
- J W Wright
- Department of Psychology, Washington State University, Pullman 99164-4820
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Wright JW, Harding JW. Brain angiotensin receptor subtypes in the control of physiological and behavioral responses. Neurosci Biobehav Rev 1994; 18:21-53. [PMID: 8170622 DOI: 10.1016/0149-7634(94)90034-5] [Citation(s) in RCA: 209] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
This review summarizes emerging evidence that supports the notion of a separate brain renin-angiotensin system (RAS) complete with the necessary precursors and enzymes for the formation and degradation of biologically active forms of angiotensins, and several binding subtypes that may mediate their diverse functions. Of these subtypes the most is known about the AT1 site which preferentially binds angiotensin II (AII) and angiotensin III (AIII). The AT1 site appears to mediate the classic angiotensin responses concerned with body water balance and the maintenance of blood pressure. Less is known about the AT2 site which also binds AII and AIII and may play a role in vascular growth. Recently, an AT3 site was discovered in cultured neoblastoma cells, and an AT4 site which preferentially binds AII(3-8), a fragment of AII now referred to as angiotensin IV (AIV). The AT4 site has been implicated in memory acquisition and retrieval, and the regulation of blood flow. In addition to the more well-studied functions of the brain RAS, we review additional less well investigated responses including regulation of cellular function, the modulation of sensory and motor systems, long term potentiation, and stress related mechanisms. Although the receptor subtypes responsible for mediating these physiologies and behaviors have not been definitively identified research efforts are ongoing. We also suggest potential contributions by the RAS to clinically relevant syndromes such as dysfunctions in the regulation of blood flow and ischemia, changes in cognitive affect and memory in clinical depressed and Alzheimer's patients, and angiotensin's contribution to alcohol consumption.
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Affiliation(s)
- J W Wright
- Department of Psychology, Washington State University, Pullman 99164-4820
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Abstract
In the present study the cardiovascular effects of intracerebroventricularly (i.c.v.) applied angiotensin II (AN II) and angiotensin III (AN III) were analysed in conscious Wistar rats. The baroreceptor heart reflex (BHR) was elicited by intravenous bolus injection of both phenylephrine (1 microgram) and sodium nitroprusside (5 micrograms) before and after i.c.v. administration (1.5 and 15 min) of the peptides. Administration of 20 ng and 200 ng AN II produced a short increase in inter-beat interval (IBI) and a long-lasting increase in mean blood pressure (MBP), inclusive of a drinking response. Only after the high dose of 200 ng AN II we found a continuous impairment in the BHR for reflex bradycardia. Inversely, the small doses of both 100 pg AN II and 100 pg AN III were without effects on IBI and MBP; they induced an enhancement in BHR for the reflex bradycardia and after 100 pg AN II it was also found for the reflex tachycardia. Pretreatment with 20 nmol amastatin (AM), a specified aminopeptidase A inhibitor, followed by 100 pg An II suppressed the enhancement in BHR. AM alone was without effects in this respect. These findings suggest that: 1) the influence of central angiotensin on the BHR could be dose-dependent in the opposite way and 2) AN III seems to be the active form and involved in the central blood pressure regulatory mechanism.
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Affiliation(s)
- E Appenrodt
- Institute of Physiology, School of Medicine, Magdeburg, Germany
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Effects of some DSIP peptide analogs on rat sleep for intraventricular infusion. Bull Exp Biol Med 1994. [DOI: 10.1007/bf02444081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Ahmed B, Kastin AJ, Banks WA, Zadina JE. CNS effects of peptides: a cross-listing of peptides and their central actions published in the journal Peptides, 1986-1993. Peptides 1994; 15:1105-55. [PMID: 7991456 DOI: 10.1016/0196-9781(94)90078-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The centrally mediated effects of peptides as published in the journal Peptides from 1986 to 1993 are tabulated in two ways. In one table, the peptides are listed alphabetically. In another table, the effects are arranged alphabetically. Most of the effects observed after administration of peptides are grouped, wherever possible, into categories such as cardiovascular and gastrointestinal. The species used in most cases has been rats; where other animals were used, the species is noted. The route of administration of peptides and source of information also are included in the tables, with a complete listing provided at the end. Many peptides have been shown to exert a large number of centrally mediated effects.
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Affiliation(s)
- B Ahmed
- VA Medical Center, New Orleans, LA 70146
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17
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Bunnemann B, Fuxe K, Ganten D. The renin-angiotensin system in the brain: an update 1993. REGULATORY PEPTIDES 1993; 46:487-509. [PMID: 8210509 DOI: 10.1016/0167-0115(93)90251-3] [Citation(s) in RCA: 87] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The renin-angiotensin system is considered to be one of the most important hormonal systems in the regulation of blood pressure and body fluid homeostasis. Ever since this system has been demonstrated to be present also in the brain, vast efforts have been made in investigating its central impact and function. The last few years, and especially the development of non-peptidic angiotensin II receptor subtype specific antagonists and the subsequent pharmacological characterization of these subtypes, brought this field of research a large step forward. This progress also might have opened up new avenues of developing highly specific anti-hypertensive drugs and thereby new ways of treating hypertension. This paper intends to provide a summary of the knowledge about the brain renin-angiotensin system accumulated during recent years; an update 1993.
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Affiliation(s)
- B Bunnemann
- Department of Histology and Neurobiology, Karolinska Institute, Stockholm, Sweden
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Wright JW, Miller-Wing AV, Shaffer MJ, Higginson C, Wright DE, Hanesworth JM, Harding JW. Angiotensin II(3-8) (ANG IV) hippocampal binding: potential role in the facilitation of memory. Brain Res Bull 1993; 32:497-502. [PMID: 8221142 DOI: 10.1016/0361-9230(93)90297-o] [Citation(s) in RCA: 156] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The present research characterizes a newly discovered ANG II(3-8) (ANG IV) binding site localized in structures associated with memory function (hippocampus, neocortex, cerebellum), as well as other brain stem structures (thalamus, inferior olivary nucleus). This site is not the AT1 or AT2 site that binds angiotensins II (ANG II) and III (ANG III) nor does it bind the nonpeptide AT1 or AT2 receptor antagonists DuP753 and PD123177, respectively. The intracerebroventricular (ICV) infusion of ANG IV was ineffective at inducing drinking in rats as compared with equivalent doses of ANG II and III. Although not as effective as ANG II or ANG III, ICV infusion of ANG IV did provoke a pressor response at the highest dose (100 pmol/min), which appeared to be mediated by ANG II (AT1)-type receptors and not the specific AIV binding site described here. By contrast, the ICV infusion of ANG IV resulted in greater effects upon retention and retrieval of a passive avoidance task as compared with ANG II. Specifically, ANG II was not different from the ICV infusion of artificial cerebrospinal fluid, while ANG IV improved retention and retrieval of this task.
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Affiliation(s)
- J W Wright
- Department of Psychology, Washington State University, Pullman 99164-4820
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Wright JW, Harding JW. Regulatory role of brain angiotensins in the control of physiological and behavioral responses. ACTA ACUST UNITED AC 1992; 17:227-62. [PMID: 1361394 DOI: 10.1016/0165-0173(92)90018-h] [Citation(s) in RCA: 226] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Considerable evidence now indicates that a separate and distinct renin-angiotensin system (RAS) is present within the brain. The necessary precursors and enzymes required for the formation and degradation of the biologically active forms of angiotensins have been identified in brain tissues as have angiotensin binding sites. Although this brain RAS appears to be regulated independently from the peripheral RAS, circulating angiotensins do exert a portion of their actions via stimulation of brain angiotensin receptors located in circumventricular organs. These circumventricular organs are located in the proximity of brain ventricles, are richly vascularized and possess a reduced blood-brain barrier thus permitting accessibility by peptides. In this way the brain RAS interacts with other neurotransmitter and neuromodulator systems and contributes to the regulation of blood pressure, body fluid homeostasis, cyclicity of reproductive hormones and sexual behavior, and perhaps plays a role in other functions such as memory acquisition and recall, sensory acuity including pain perception and exploratory behavior. An overactive brain RAS has been identified as one of the factors contributing to the pathogenesis and maintenance of hypertension in the spontaneously hypertensive rat (SHR) model of human essential hypertension. Oral treatment with angiotensin-converting enzyme inhibitors, which interfere with the formation of angiotensin II, prevents the development of hypertension in young SHR by acting, at least in part, upon the brain RAS. Delivery of converting enzyme inhibitors or specific angiotensin receptor antagonists into the brain significantly reduces blood pressure in adult SHR. Thus, if the SHR is an appropriate model of human essential hypertension (there is controversy concerning its usefulness), the potential contribution of the brain RAS to this dysfunction must be considered during the development of future antihypertensive compounds.
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Affiliation(s)
- J W Wright
- Department of Psychology, Washington State University, Pullman 99164-4820
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Swanson GN, Hanesworth JM, Sardinia MF, Coleman JK, Wright JW, Hall KL, Miller-Wing AV, Stobb JW, Cook VI, Harding EC. Discovery of a distinct binding site for angiotensin II (3-8), a putative angiotensin IV receptor. REGULATORY PEPTIDES 1992; 40:409-19. [PMID: 1438983 DOI: 10.1016/0167-0115(92)90527-2] [Citation(s) in RCA: 201] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We report here the discovery of a unique and novel angiotensin binding site and peptide system based upon the C-terminal 3-8 hexapeptide fragment of angiotensin II (NH3(+)-Val-Tyr-Ile-His-Pro-Phe-COO-) (AII(3-8) (AIV)). This fragment binds saturably, reversibly, specifically, and with high affinity to membrane-binding sites in a variety of tissues and from many species. The binding site is pharmacologically distinct from the classic angiotensin receptors (AT1 or AT2) displaying low affinity for the known agonists (AII and AIII) and antagonist (Sar1,Ile8-AII). Although a definitive function has not been assigned to this system in many of the tissues in which it resides, AIV's interaction with endothelial cells may involve a role in endothelial cell-dependent vasodilation. Consequent to this action, AIV is a potent stimulator of renal cortical blood flow.
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Affiliation(s)
- G N Swanson
- Department of Veterinary and Comparative Anatomy, Washington State University, Pullman 99164-6520
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Harding JW, Cook VI, Miller-Wing AV, Hanesworth JM, Sardinia MF, Hall KL, Stobb JW, Swanson GN, Coleman JK, Wright JW. Identification of an AII(3-8) [AIV] binding site in guinea pig hippocampus. Brain Res 1992; 583:340-3. [PMID: 1504842 DOI: 10.1016/s0006-8993(10)80047-2] [Citation(s) in RCA: 118] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A unique angiotensin binding site specific for the hexapeptide, AII(3-8), has been identified in guinea pig hippocampus. This binding site, which is present in the pyramidal cell layer of CA1, CA2, CA3 of the hippocampus and dentate gyrus, binds AII(3-8) with high affinity (KD = 1.29 +/- 0.18 nM) in a saturable manner (Bmax = 449 +/- 62 fmol/mg protein). The N-terminal structure of the binding ligand is paramount in determining the binding affinity. The C-terminal requirements seem less stringent as evidenced by the binding affinity of AII(3-7) (KD = 20.9 +/- 2.1 nM). Neither AII, AIII,Sar1, Ile8-AII, Dup 753 nor CGP42112A appear to bind, indicating that this binding site is neither the AT1 nor AT2 sites described for AII/AIII. Autoradiographic analysis of hippocampus binding confirms the inability of Sar1,Ile8-AII to compete for [125I]AII(3-8) binding. Conversely AII(3-8) was unable to displace [125I]Sar1,Ile8-AII binding.
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Affiliation(s)
- J W Harding
- Department of Veterinary and Comparative Anatomy, Washington State University, Pullman 99164-6520
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Wright JW, Amir HZ, Murray CE, Roberts KA, Harding JW, Mizutani S, Ward PE. Use of aminopeptidase M as a hypotensive agent in spontaneously hypertensive rats. Brain Res Bull 1991; 27:545-51. [PMID: 1684525 DOI: 10.1016/0361-9230(91)90027-h] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The present investigation determined that a commercially available aminopeptidase M (AmM, Sigma Chemical) can be utilized to lower blood pressure in normotensive and hypertensive rats. In vitro analyses indicated that the predominant peptidase present in this preparation was AmM; however, it also contained some aminopeptidase A (AmA) and less DAP IV. Although no DAP IV-mediated metabolism of angiotensin II (AII) or angiotensin III (AIII) was measured, both AmM and AmA metabolized AII and AIII. Upon further examination, it appeared that AII could be converted to AIII by either AmM or AmA; however, Arg was cleaved from the N-Terminal of AIII predominantly by AmM. The aminopeptidase inhibitors actinonin (AC), amastatin (AM), and bestatin (BE) effectively blocked the AmM-induced hydrolysis of the Asp-Arg bond of AII, and the Arg-Val bond of AIII. The activity of AmA was inhibited by AM but was relatively resistant to inhibition by AC and BE. Next, exogenous aminopeptidase replacement was employed in the anesthetized spontaneously hypertensive rat (SHR) in an attempt to temporarily correct a hypothesized brain deficiency of receptor-associated peptidases and lower blood pressure. Third-ventricle infusion of AmM produced significant drops in blood pressure and heart rate in both SHRs and Wistar-Kyoto normotensive controls. Pretreatment with AC or BE was particularly effective at interfering with the subsequent AmM-induced hypotensive effect, while AM was less effective. The central mechanisms underlying these effects are in need of further investigation; however, they are at least partially dependent upon the brain angiotensin system.
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Affiliation(s)
- J W Wright
- Department of Psychology, Washington State University, Pullman 99164-4820
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Pompei P, Polidori C, Perfumi M, Massi M. Sensitivity of spontaneously hypertensive and of Wistar Kyoto rats to the antidipsogenic action of eledoisin. REGULATORY PEPTIDES 1990; 28:119-29. [PMID: 2326504 DOI: 10.1016/0167-0115(90)90069-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
This study investigated the sensitivity of spontaneously hypertensive rats (SHR) and of Wistar Kyoto rats (WKR) to the antidipsogenic action of the tachykinin eledoisin (ELE). Drinking was evoked by: (a) intracerebroventricular (i.c.v.) injection of angiotensin II, (b) subcutaneous (s.c.) administration of hypertonic NaCl (1.5 M; 1 ml/100 g b.wt.) or (c) 18 h of water deprivation with free access to food. In accordance with previous studies, the dipsogenic effect of all three treatments was exaggerated in the SHR. And when treated with i.c.v. ELE (12.5-25 ng/rat) they were far less sensitive than WKR to its antidipsogenic action on angiotensin-induced drinking. Smaller differences in strain sensitivity were also observed for the effect of ELE on cell dehydration- and on water deprivation-induced drinking, but only at the dose of 200 and 50 ng/rat, respectively. The different sensitivity of the SHR to the antidipsogenic effect of ELE supports the idea that tachykininergic mechanisms for control of water intake are differently regulated in the SHR than they are in the normotensive WKR.
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Affiliation(s)
- P Pompei
- Istituto di Farmacologia, Università di Camerino, Italy
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