1
|
Kraynak M, Willging MM, Kuehlmann AL, Kapoor AA, Flowers MT, Colman RJ, Levine JE, Abbott DH. Aromatase Inhibition Eliminates Sexual Receptivity Without Enhancing Weight Gain in Ovariectomized Marmoset Monkeys. J Endocr Soc 2022; 6:bvac063. [PMID: 35592515 PMCID: PMC9113444 DOI: 10.1210/jendso/bvac063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Indexed: 11/19/2022] Open
Abstract
Context Ovarian estradiol supports female sexual behavior and metabolic function. While ovariectomy (OVX) in rodents abolishes sexual behavior and enables obesity, OVX in nonhuman primates decreases, but does not abolish, sexual behavior, and inconsistently alters weight gain. Objective We hypothesize that extra-ovarian estradiol provides key support for both functions, and to test this idea, we employed aromatase inhibition to eliminate extra-ovarian estradiol biosynthesis and diet-induced obesity to enhance weight gain. Methods Thirteen adult female marmosets were OVX and received (1) estradiol-containing capsules and daily oral treatments of vehicle (E2; n = 5); empty capsules and daily oral treatments of either (2) vehicle (VEH, 1 mL/kg, n = 4), or (3) letrozole (LET, 1 mg/kg, n = 4). Results After 7 months, we observed robust sexual receptivity in E2, intermediate frequencies in VEH, and virtually none in LET females (P = .04). By contrast, few rejections of male mounts were observed in E2, intermediate frequencies in VEH, and high frequencies in LET females (P = .04). Receptive head turns were consistently observed in E2, but not in VEH and LET females. LET females, alone, exhibited robust aggressive rejection of males. VEH and LET females demonstrated increased % body weight gain (P = .01). Relative estradiol levels in peripheral serum were E2 >>> VEH > LET, while those in hypothalamus ranked E2 = VEH > LET, confirming inhibition of local hypothalamic estradiol synthesis by letrozole. Conclusion Our findings provide the first evidence for extra-ovarian estradiol contributing to female sexual behavior in a nonhuman primate, and prompt speculation that extra-ovarian estradiol, and in particular neuroestrogens, may similarly regulate sexual motivation in other primates, including humans.
Collapse
Affiliation(s)
- Marissa Kraynak
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, WI 53715, USA
- Endocrinology-Reproductive Physiology Training Program, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Molly M Willging
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, WI 53715, USA
- Endocrinology-Reproductive Physiology Training Program, University of Wisconsin-Madison, Madison, WI 53715, USA
- Center for Women’s Health, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Alex L Kuehlmann
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Amita A Kapoor
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Matthew T Flowers
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Ricki J Colman
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, WI 53715, USA
- Endocrinology-Reproductive Physiology Training Program, University of Wisconsin-Madison, Madison, WI 53715, USA
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Jon E Levine
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, WI 53715, USA
- Endocrinology-Reproductive Physiology Training Program, University of Wisconsin-Madison, Madison, WI 53715, USA
- Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - David H Abbott
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, WI 53715, USA
- Endocrinology-Reproductive Physiology Training Program, University of Wisconsin-Madison, Madison, WI 53715, USA
- Department of Obstetrics and Gynecology, University of Wisconsin-Madison, Madison, WI 53715, USA
| |
Collapse
|
2
|
Veening JG, Olivier B. Intranasal administration of oxytocin: behavioral and clinical effects, a review. Neurosci Biobehav Rev 2013; 37:1445-65. [PMID: 23648680 PMCID: PMC7112651 DOI: 10.1016/j.neubiorev.2013.04.012] [Citation(s) in RCA: 133] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 04/22/2013] [Accepted: 04/24/2013] [Indexed: 12/11/2022]
Abstract
The mechanisms behind the effects of IN-applied substances need more attention. The mechanisms involved in the brain-distribution of IN-OT are completely unexplored. The possibly cascading effects of IN-OT on the intrinsic OT-system require serious investigation. IN-OT induces clear and specific changes in neural activation. IN-OT is a promising approach to treat certain clinical symptoms.
The intranasal (IN-) administration of substances is attracting attention from scientists as well as pharmaceutical companies. The effects are surprisingly fast and specific. The present review explores our current knowledge about the routes of access to the cranial cavity. ‘Direct-access-pathways’ from the nasal cavity have been described but many additional experiments are needed to answer a variety of open questions regarding anatomy and physiology. Among the IN-applied substances oxytocin (OT) has an extensive history. Originally applied in women for its physiological effects related to lactation and parturition, over the last decade most studies focused on their behavioral ‘prosocial’ effects: from social relations and ‘trust’ to treatment of ‘autism’. Only very recently in a microdialysis study in rats and mice, the ‘direct-nose-brain-pathways’ of IN-OT have been investigated directly, implying that we are strongly dependent on results obtained from other IN-applied substances. Especially the possibility that IN-OT activates the ‘intrinsic’ OT-system in the hypothalamus as well needs further clarification. We conclude that IN-OT administration may be a promising approach to influence human communication but that the existing lack of information about the neural and physiological mechanisms involved is a serious problem for the proper understanding and interpretation of the observed effects.
Collapse
Affiliation(s)
- Jan G Veening
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, P.O. Box 80082, 3508 TB, Utrecht, The Netherlands; Department of Anatomy (109), Radboud University of Medical Sciences, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands.
| | | |
Collapse
|
3
|
Shingaki T, Hidalgo IJ, Furubayashi T, Sakane T, Katsumi H, Yamamoto A, Yamashita S. Nasal delivery of P-gp substrates to the brain through the nose-brain pathway. Drug Metab Pharmacokinet 2011; 26:248-55. [PMID: 21317541 DOI: 10.2133/dmpk.dmpk-10-rg-108] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The objective of this study was to evaluate in rats the potential utility of the nasal route to enhance central nervous system (CNS) delivery of drugs recognized by P-glycoprotein (P-gp). Well-known P-gp substrates verapamil and talinolol were perfused nasally or infused intravenously, and when plasma concentrations following intravenous infusion and nasal perfusion showed similar profiles. The concentration of verapamil in the brain after nasal perfusion was twice that after intravenous infusion. Although talinolol in the brain and the cerebrospinal fluid after i.v. infusion were below the detection limit, it was detected after nasal perfusion. When rats were treated with cyclosporin A, brain concentrations of verapamil after both administration modes were increased significantly, while those of talinolol were not significantly changed. Since the permeability of talinolol is low, talinolol in the brain which was transported directly from the nasal cavity has little chance of transport by P-gp localized in the apical membrane of cerebral microvessel endothelial cells. The potential for drug delivery utilizing the nose-CNS route was confirmed for P-gp substrates. The advantage of nasal delivery over i.v. delivery of talinolol to the brain was more significant than that of verapamil, suggesting that nasal administration is more useful strategy for the brain delivery of low-permeability P-gp substrates than the use of P-gp inhibitors.
Collapse
|
4
|
Merkus FWHM, van den Berg MP. Can nasal drug delivery bypass the blood-brain barrier?: questioning the direct transport theory. Drugs R D 2007; 8:133-44. [PMID: 17472409 DOI: 10.2165/00126839-200708030-00001] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
The connection between the nasal cavity and the CNS by the olfactory neurones has been investigated extensively during the last decades with regard to its feasibility to serve as a direct drug transport route to the CSF and brain. This drug transport route has gained much interest as it may circumvent the blood-brain barrier (BBB), which prevents some drugs from entering the brain. Approximately 100 published papers mainly reporting animal experiments were reviewed to evaluate whether the experimental design used and the results generated provided adequate pharmacokinetic information to assess whether the investigated drug was transported directly from the olfactory area to the CNS. In the analysis the large anatomical differences between the olfactory areas of animals and humans and the experimental conditions used were evaluated. The aim of this paper was to establish the actual evidence for the feasibility of this direct transport route in humans. Twelve papers presented a sound experimental design to study direct nose to CNS transport of drugs based on the authors' criteria. Of these, only two studies in rats were able to provide results that can be seen as an indication for direct transport from the nose to the CNS. No pharmacokinetic evidence could be found to support a claim that nasal administration of drugs in humans will result in an enhanced delivery to their target sites in the brain compared with intravenous administration of the same drug under similar dosage conditions.
Collapse
Affiliation(s)
- Frans W H M Merkus
- Leiden/Amsterdam Centre for Drug Research, Leiden University, Leiden, The Netherlands.
| | | |
Collapse
|
5
|
van den Berg MP, Verhoef JC, Romeijn SG, Merkus FWHM. Uptake of estradiol or progesterone into the CSF following intranasal and intravenous delivery in rats. Eur J Pharm Biopharm 2004; 58:131-5. [PMID: 15207546 DOI: 10.1016/j.ejpb.2004.02.010] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2003] [Accepted: 02/02/2004] [Indexed: 10/26/2022]
Abstract
The uptake of estradiol and progesterone into the cerebrospinal fluid (CSF) after intranasal and intravenous administration in rats was investigated. Each animal received estradiol intranasally (40 microg/rat) and by intravenous infusion (10 microg/rat) into the jugular vein using a vascular access port. Hereafter, the same set of rats was treated with progesterone intranasally (200 microg/rat) and by intravenous infusion (104 microg/rat). Following nasal delivery, both steroid hormones reach Cmax values in plasma and CSF at 15 min after administration. Intravenous infusion of estradiol and progesterone shows comparable plasma and CSF concentration-time profiles compared to the nasal route. For both hormones the AUCCSF/AUCplasma ratios (mean +/- SD) after intranasal delivery (estradiol 2.3 +/- 1.1%; progesterone 1.9 +/- 0.7%) do not differ significantly from the ratios shown after intravenous infusion (estradiol 2.0 +/- 0.6%; progesterone 2.2 +/- 0.8%). These results indicate that after nasal delivery estradiol and progesterone are rapidly absorbed into the systemic circulation, from where the non-protein bound hormones probably enter the CSF by crossing the blood-brain barrier. No extra direct nose-CSF transport could be demonstrated.
Collapse
Affiliation(s)
- Mascha P van den Berg
- Department of Pharmaceutical Technology and Biopharmaceutics, Leiden/Amsterdam Centre for Drug Research, Leiden University, Leiden, The Netherlands
| | | | | | | |
Collapse
|
6
|
Mathison S, Nagilla R, Kompella UB. Nasal route for direct delivery of solutes to the central nervous system: fact or fiction? J Drug Target 1998; 5:415-41. [PMID: 9783675 DOI: 10.3109/10611869808997870] [Citation(s) in RCA: 122] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
During this century, several investigators reported that certain viruses, metals, drugs, and other solutes could bypass systemic circulation and enter the brain and/or cerebrospinal fluid directly following nasal administration. Although evidence clearly suggests that the olfactory epithelium and its olfactory cells play a major role, little is known about the mechanisms of direct transport of solutes into the brain. An overview of what is known about these mechanisms may aid in further research in this field, including studies of direct drug delivery to the central nervous system. This review, in addition to summarizing the literature to date, clearly describes the intricate association of the anatomical features involved in direct entry of solutes into the brain following nasal administration. To aid in the understanding of the possible routes a solute can take after nasal administration, the anatomy of the olfactory epithelium and surrounding tissues is described, and a detailed scheme delineating the emerging pathways is presented. Techniques used in delineating these pathways and studies supporting a particular pathway are discussed in greater detail. Finally, some factors influencing the direct transport of solutes to the cerebrospinal fluid and brain are summarized.
Collapse
Affiliation(s)
- S Mathison
- Department of Chemistry, Auburn University, AL 36849-5503, USA
| | | | | |
Collapse
|
7
|
Abstract
Recently, the delivery of xenobiotics via the nasal route has received increasing attention as this offers several advantages, i.e. high systemic availability, rapid onset of action. Both charged and uncharged forms of drugs can be transported across the nasal epithelium. This mucosa is rich in various metabolizing enzymes such as aldehyde dehydrogenase, glutathione transferases, epoxide hydrolases, cyt-P450-dependent monooxygenases. The presence of these enzymes may make it possible for pharmaceutical scientists to design prodrugs for better absorption and high systemic availability. Recent advances in peptide nasal delivery through prodrug modification has been thoroughly discussed in this paper. Finally, nasally delivered therapeutic agents targeted to various disease states have been examined.
Collapse
Affiliation(s)
- AK Mitra
- Department of Pharmaceutical Sciences, University of Missouri-Kansas City, 5100 Rockhill Road, Kansas City, MO 64110-2499, USA
| | | |
Collapse
|
8
|
Kumar TC, Shah RS, Chitlange SM, Hazari KT, Gopalkrishnan K, Vadigoppula AD, Vernekar VJ, Borkar DM, Puri CP. Effects of intranasal administration of norethisterone on folliculogenesis, cervical mucus, vaginal cytology, endometrial morphology and reproductive-endocrine profile in women. Contraception 1991; 44:245-67. [PMID: 1764942 DOI: 10.1016/0010-7824(91)90016-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The effects of intranasal administration of norethisterone (NET) on menstrual cycle length, folliculogenesis, serum levels of estradiol, FSH, LH and progesterone, vaginal cytology, cervical mucus and endometrial morphology were studied in 8 volunteers (age 28 to 39 years, weighing between 46 and 54 kg). The study period comprised 4 consecutive menstrual cycles. In the first cycle (pretreatment cycle), only the vehicle (alcohol, propylene glycol, water; 3:3:4) was sprayed intranasally (100 microliters in each nostril), using a metered nebulizer, once daily from day 3 to the last day of menstrual cycle. In the next two cycles (treatment cycles), NET (300 micrograms/day) was administered once daily, starting from day one of menstrual cycle, between 9 and 10 a.m. The fourth cycle was a post-treatment cycle in which the volunteers were monitored for recovery. Blood samples (about 5 ml each) were collected once daily from day 8 to 24 and thereafter on alternate days until the last day of cycle during all the 4 cycles. Levels of estradiol, FSH, LH and progesterone were measured in the serum samples by radioimmunoassay methods. Cervical mucus samples and vaginal smears were collected once daily starting from day 7 or 8 of each cycle until the mucus was very scanty. Serial pelvic ultrasonography was performed starting from day 7 or 8 until the growing follicle disappeared or throughout the cycle in case a growing follicular cyst was observed. Endometrial aspirates were collected once around day 22 in each cycle and processed for routine histological examination.
Collapse
Affiliation(s)
- T C Kumar
- Institute for Research in Reproduction (ICMR), Parel, Bombay, India
| | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Schipper NG, Verhoef JC, Merkus FW. The nasal mucociliary clearance: relevance to nasal drug delivery. Pharm Res 1991; 8:807-14. [PMID: 1924131 DOI: 10.1023/a:1015830907632] [Citation(s) in RCA: 139] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Mucociliary clearance is an important physiological defense mechanism of the respiratory tract to protect the body against noxious inhaled materials. This process is responsible for the rapid clearance of nasally administered drugs from the nasal cavity to the nasopharynx, thereby interfering with the absorption of drugs following intranasal application. This review describes the mucociliary system and the methods used for its characterization. Examples are given of the effects of drugs and additives on its functioning. Further, possible approaches are presented for increasing the residence time of drugs in the nasal cavity, thereby improving intranasal drug delivery.
Collapse
Affiliation(s)
- N G Schipper
- Center for Bio-Pharmaceutical Sciences, Leiden University, The Netherlands
| | | | | |
Collapse
|
10
|
Hermens WA, Deurloo MJ, Romeyn SG, Verhoef JC, Merkus FW. Nasal absorption enhancement of 17 beta-estradiol by dimethyl-beta-cyclodextrin in rabbits and rats. Pharm Res 1990; 7:500-3. [PMID: 2367318 DOI: 10.1023/a:1015816716544] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A new formulation for nasal administration containing 17 beta-estradiol (E2) with dimethyl-beta-cyclodextrin (DM beta C) as a solubilizer and absorption enhancer is described. Nasal administration of this E2-DM beta C formulation gave a significantly higher E2 absorption than an E2 suspension in both rabbits and rats. Relative to an intravenous injection of the E2-DM beta C formulation, absolute bioavailabilities of 94.6 and 67.2% were calculated for the nasal E2-DM beta C formulation in rabbits and rats, respectively. Differences in bioavailability may have resulted from differences in experimental animal conditions. The effects on human nasal ciliary activity of the E2-DM beta C formulation were studied with an in vitro method. The formulation was found to exert only a minor effect on ciliary beat frequency. Thus, nasal delivery of E2, using a cyclodextrin inclusion formulation, may have potential for clinical application, e.g., in the therapy of postmenopausal disorders.
Collapse
Affiliation(s)
- W A Hermens
- Center for Bio-Pharmaceutical Sciences, Leiden University, The Netherlands
| | | | | | | | | |
Collapse
|
11
|
Ohman L, Edqvist LE, Johansson ED. Absorption of topically applied hydrocortisone from the eye of the rhesus monkey. Acta Ophthalmol 1982; 60:106-12. [PMID: 7136521 DOI: 10.1111/j.1755-3768.1982.tb05786.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Blood samples were collected from anaesthetized monkeys during one h a) after topical application of an eyedrop of hydrocortisone acetate suspension, b) after topical application of a drop of the vehicle alone, and c) after no application at all. Radioimmunoassay (RIA) showed a rapid and similar increase of hydrocortisone plasma levels in all 3 kinds of experiments. RIA revealed that in monkeys the anaesthetic procedure alone was sufficient to cause a considerable increase of endogenous hydrocortisone levels overshadowing any systemic absorption of topical hydrocortisone. Using tritiated hydrocortisone instead a rapid increase of systemic absorption after topical application was found. A plasma concentration of 1% of the dose was found one min after topical instillation increasing to a maximum of 6-7% at 30 min. The half time of the show phase of elimination was about 19 h.
Collapse
|