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Pimentel PB, Santigo CS, Ferraz JF, Morielle-Versute E, Taboga SR, Souza CC, Beguelini MR. Morphophysiology of the male reproductive accessory glands of the bat Pteronotus gymnonotus (Mormoopidae: Chiroptera). Tissue Cell 2023; 80:101991. [PMID: 36462383 DOI: 10.1016/j.tice.2022.101991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 11/23/2022] [Accepted: 11/24/2022] [Indexed: 11/27/2022]
Abstract
Mormoopidae is an exclusive Neotropical family of bats, distributed from southern Mexico to northeastern Brazil. Possibly due to its endemic distribution and very low occurrence (rarity), descriptions of their reproductive accessory glands (RAGs) are still lacking. Thus, this study aims to characterize the male RAGs of Pteronotus gymnonotus (Mormoopidae: Chiroptera). Results demonstrate that the RAGs of P. gymnonotus is composed of a prostatic complex, comprising two regions (ventral and dorsal prostates); urethral (Littre) glands, a pair of bulbourethral and ampullary glands, with the absence of seminal vesicles. The ventral prostate has an atypical epithelium, due to its holocrine secretion; which contains numerous PAS-positive globular vesicles. The dorsal prostate has a cubic-to-columnar pseudostratified epithelium, containing fluid PAS-negative secretion. The ampullary glands present cubic-to-columnar pseudostratified epithelium, with secretion varying from granular and PAS-negative to fluid and PAS-positive. Urethral glands are dispersed in the submucosa of the urethra, while the bulbourethral glands are located in the penile root. Both glands have cubic-to-columnar pseudostratified epithelium with PAS-positive globular secretion. In conclusion, we propose that the RAGs of P. gymnonotus possibly evolved from a common emballonurid ancestor, shared with the families Phyllostomidae and Noctilionidae, but with the development of an exclusive apomorphy, the ampullary glands.
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Affiliation(s)
- Pollyana B Pimentel
- Center of Biological and Health Science, UFOB - Universidade Federal do Oeste da Bahia, Barreiras, Bahia, Brazil.
| | - Cornélio S Santigo
- Center of Biological and Health Science, UFOB - Universidade Federal do Oeste da Bahia, Barreiras, Bahia, Brazil.
| | - Juliana F Ferraz
- Center of Biological and Health Science, UFOB - Universidade Federal do Oeste da Bahia, Barreiras, Bahia, Brazil.
| | - Eliana Morielle-Versute
- Department of Zoology and Botany, UNESP - Univ. Estadual Paulista, São José do Rio Preto, São Paulo, Brazil.
| | - Sebastião R Taboga
- Department of Biology, UNESP - Univ. Estadual Paulista, São José do Rio Preto, São Paulo, Brazil.
| | - Carolina C Souza
- Center of Biological and Health Science, UFOB - Universidade Federal do Oeste da Bahia, Barreiras, Bahia, Brazil.
| | - Mateus R Beguelini
- Center of Biological and Health Science, UFOB - Universidade Federal do Oeste da Bahia, Barreiras, Bahia, Brazil.
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Greville LJS, Bueno LM, Pollock T, Faure PA. Quantification of Urinary Sex Steroids in the Big Brown Bat ( Eptesicus fuscus). Physiol Biochem Zool 2021; 95:22-34. [PMID: 34843427 DOI: 10.1086/717896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractBats (order Chiroptera) are the second largest group of mammals, diverging ~52.5 million years ago. Many species exhibit an unusual reproductive cycle and extreme longevity without reproductive senescence, yet steroid profiles exist for few bats. Big brown bats (Eptesicus fuscus) are temperate insectivores found throughout North America. They mate promiscuously in fall, store sperm during winter hibernation, and have delayed ovulation and fertilization in spring. Here, we report the first urinary steroid profile in bats by quantifying 17β-estradiol (E2) in captive male and female E. fuscus across their reproductive cycle. Male bats had higher urinary E2 levels than females, and adults had higher levels than yearlings following creatinine adjustment for hydration. In nonpregnant females, several seasonal differences in creatinine-adjusted and unadjusted urinary E2 levels were observed. Urinary E2 was higher in males than females in winter for both conditions and in autumn for creatinine-adjusted levels. We quantified progesterone (P4) in a subset of females. In nonpregnant females, urinary P4 was constant across seasons except for unadjusted levels, which were highest in the summer. In pregnant females, urinary E2 and P4 levels peaked beginning ~20 d before parturition, with both steroids returning to baseline in the following weeks. Knowing how urinary steroid levels fluctuate with age and sex and across the annual season is key to understanding reproductive cycling in bats. Our research furthers the potential for bats as a model for medical reproductive research. Moreover, it complements previous studies on the potential role of steroids in primer pheromonal effects in bats.
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Greville LJ, Tam AG, Faure PA. Evaluating odour and urinary sex preferences in the big brown bat (Eptesicus fuscus). CAN J ZOOL 2021. [DOI: 10.1139/cjz-2021-0067] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Olfactory cues provide detailed information to mammals regarding conspecifics. Bats may identify species, colony membership, and individuals using olfaction. Big brown bats (Eptesicus fuscus (Palisot de Beauvois, 1796)) live in mixed-sex colonies and must differentiate between sexes to locate mates. We hypothesized that odour cues convey information about sex. In experiment 1, adult E. fuscus were recorded exploring a Y-maze that contained general body odours sampled from male or female conspecifics. One group of subjects was habituated to the Y-maze prior to experimental trials, whereas a second group was not. Bat exploration and the proportion of time spent near each scent were used as preference indicators for the body odour of a particular sex. Experiment 2 followed similar procedures except the odour cue tested was urine from either male or female conspecifics and without Y-maze habituation. Results found no evidence that E. fuscus prefer the body odours of a given sex, but females did prefer the odour of male urine. Non-habituated animals in experiment 1 were more likely to explore the Y-maze and approach a stimulus scent compared with habituated bats. These findings have important implications for courtship and mating behaviour in bats, as well for designing future behavioural studies.
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Affiliation(s)
- Lucas J.S. Greville
- Department of Psychology, Neuroscience and Behaviour, McMaster University, Hamilton, ON L8S 4K1, Canada
- Department of Psychology, Neuroscience and Behaviour, McMaster University, Hamilton, ON L8S 4K1, Canada
| | - Audrey G. Tam
- Department of Psychology, Neuroscience and Behaviour, McMaster University, Hamilton, ON L8S 4K1, Canada
- Department of Psychology, Neuroscience and Behaviour, McMaster University, Hamilton, ON L8S 4K1, Canada
| | - Paul A. Faure
- Department of Psychology, Neuroscience and Behaviour, McMaster University, Hamilton, ON L8S 4K1, Canada
- Department of Psychology, Neuroscience and Behaviour, McMaster University, Hamilton, ON L8S 4K1, Canada
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Edwards PD, Arguelles DA, Mastromonaco GF, Holmes MM. Queen pregnancy increases group estradiol levels in cooperatively breeding naked mole-rats. Integr Comp Biol 2021; 61:1841-1851. [PMID: 34048558 DOI: 10.1093/icb/icab106] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
For cooperative species, there can be great value in the synchronization of physiological states to coordinate group behavioral states. This is evident in naked mole-rats (Heterocephalus glaber), which have the most extreme form of cooperative breeding in mammals. Colonies have a single reproductive female, "the queen", and 1-3 breeding males. These breeders are supported by adult "subordinates," which are all socially suppressed into a prepubertal state. Subordinates cooperate in colony maintenance, defense, and alloparental care. Prior work has reported that there may be social sharing of hormones among individuals in the colony because when the queen is pregnant, subordinates of both sexes develop enlarged nipples and female subordinates can develop vaginal perforation. We sought to document the hormonal changes and mechanisms behind these observations. We found that subordinate estradiol levels were elevated during the queen's pregnancy and were correlated with queen levels. To determine if this occurs by direct hormone-sharing, where group members uptake the hormones of conspecifics through excreta or the skin, we then tested whether treating a single subordinate in the colony with estradiol would induce the same effect in other colony members. It did not, which indicates that the influence on group estradiol levels may be specific to cues from the queen. These queen cues may be behavioral in nature, as we found that queens were less aggressive during pregnancy, which prior work has suggested may relax reproductive suppression of subordinates. Yet levels of queen aggression alone were not associated, or were weakly associated, with their colony's estradiol levels, though our sample size examining this particular relationship was low. This is suggestive that additional queen cues of reproductive status, beyond just aggression, may be relevant in influencing the subordinate hormonal change, or that the relationship between aggression and colony estradiol levels is more subtle and would need to be elucidated with a larger sample size. These results have implications for how cooperative breeders coordinate reproduction and alloparental care, and how social cues can influence individual and group physiology.
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Affiliation(s)
- Phoebe D Edwards
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON Canada
| | - Daphne A Arguelles
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON Canada
| | | | - Melissa M Holmes
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON Canada.,Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, ON Canada
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Greville LJ, Pollock T, Faure PA, deCatanzaro D. Seasonal transfer and quantification of urinary estradiol in the big brown bat (Eptesicus fuscus). Gen Comp Endocrinol 2020; 286:113321. [PMID: 31733210 DOI: 10.1016/j.ygcen.2019.113321] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 09/24/2019] [Accepted: 11/12/2019] [Indexed: 10/25/2022]
Abstract
Growing evidence shows that sex steroids not only act within the individual whose glands produce them; they can also act on proximate conspecifics. Previous studies show that exogenous 17β-estradiol (E2) can be absorbed both nasally and percutaneously, arriving in blood, neural, reproductive, and peripheral tissues. When male bats were injected with radiolabeled E2 (3H-E2) and housed with females during the mating season, radioactivity was reliably measured in the females' tissues. The present study was designed to compare E2 transfer from male to female bats at three time points in the annual reproductive cycle: spring (ovulation and fertilization), summer (maternal season), and autumn (mating season). Pairs of mature female bats were housed with a mature 3H-E2-treated male (50 μCi). Following 48 h of communal housing, radioactivity was measured in the tissues of female bats. Higher levels of radioactivity were present in the uterus and other tissues during the spring and autumn seasons compared to the summer season. We also measured natural levels of bioactive, unconjugated E2 in the urine of male bats using enzyme immunoassays, and found that it was present in all three seasons but at lower levels during the summer. Male-excreted E2 could transfer to females within the close confines of a roost, potentially influencing their reproductive physiology and behavior. These results suggest increased E2 transfer coincides with female reproduction, with urine as a likely vector. We suggest that sex steroid transfer among interacting individuals may explain several mammalian phenomena historically viewed as "pheromonal".
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Affiliation(s)
- Lucas J Greville
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - Tyler Pollock
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - Paul A Faure
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - Denys deCatanzaro
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario L8S 4K1, Canada.
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Affiliation(s)
- Thomas E Tomasi
- Department of Biology, Missouri State University, Springfield, MO, USA
| | - Briana N Anderson
- Department of Biology, Missouri State University, Springfield, MO, USA
| | - Theodore Garland
- Department of Evolution, Ecology, and Organismal Biology, University of California – Riverside, Riverside, CA, USA
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Male Scent Gland Signals Mating Status in Greater Spear-Nosed Bats, Phyllostomus hastatus. J Chem Ecol 2018; 44:975-986. [DOI: 10.1007/s10886-018-1003-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 07/27/2018] [Accepted: 07/30/2018] [Indexed: 12/24/2022]
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8
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Pollock T, Greville LJ, Weaver RE, Radenovic M, deCatanzaro D. Bisphenol S modulates concentrations of bisphenol A and oestradiol in female and male mice. Xenobiotica 2018; 49:540-548. [DOI: 10.1080/00498254.2018.1480818] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Tyler Pollock
- Department of Psychology Neuroscience & Behaviour, McMaster University, Hamilton, Canada
| | - Lucas J. Greville
- Department of Psychology Neuroscience & Behaviour, McMaster University, Hamilton, Canada
| | - Rachel E. Weaver
- Department of Psychology Neuroscience & Behaviour, McMaster University, Hamilton, Canada
| | - Marija Radenovic
- Department of Psychology Neuroscience & Behaviour, McMaster University, Hamilton, Canada
| | - Denys deCatanzaro
- Department of Psychology Neuroscience & Behaviour, McMaster University, Hamilton, Canada
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Pollock T, Weaver RE, Ghasemi R, deCatanzaro D. A mixture of five endocrine-disrupting chemicals modulates concentrations of bisphenol A and estradiol in mice. CHEMOSPHERE 2018; 193:321-328. [PMID: 29145094 DOI: 10.1016/j.chemosphere.2017.11.030] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 11/05/2017] [Accepted: 11/07/2017] [Indexed: 06/07/2023]
Abstract
Most people in developed countries are exposed to multiple endocrine-disrupting synthetic chemicals. We previously showed that a single dose of triclosan, tetrabromobisphenol A (TBBPA), butyl paraben, propyl paraben, or di(2-ethylhexyl) phthalate elevated concentrations of bisphenol A (BPA) in mice. Here we investigated whether concurrent exposure to lower doses of these five chemicals could modulate concentrations of bisphenol A (BPA) or the natural estrogen, 17β-estradiol (E2). CF1 mice were injected subcutaneously with 0.1 or 0.5 mg of one chemical, or a 0.5 mg mixture containing 0.1 mg of each of all five chemicals, then given dietary 50 μg kg-114C-BPA. The mixture elevated 14C-BPA concentrations in the lungs, muscle, uterus, ovaries, kidney, and blood serum of female mice. When administered alone, triclosan and TBBPA elevated 14C-BPA concentrations in the uterus, ovaries, and blood serum. In another experiment, CF1 mice were injected subcutaneously with the 0.5 mg mixture containing 0.1 mg of all five chemicals, then E2 was measured in urine 2-12 h later. The mixture elevated E2 at 8 h after injection in female mice. No treatments significantly altered concentrations of 14C-BPA or E2 in male mice. These data show that these endocrine-disrupting chemicals interact in vivo, magnifying one another's effects, consistent with inhibition of enzymes that are critical for estrogen metabolism. These findings highlight the importance of considering exposure to multiple chemicals when assessing health outcomes and determining regulatory exposure limits.
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Affiliation(s)
- Tyler Pollock
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario, Canada.
| | - Rachel E Weaver
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario, Canada
| | - Ramtin Ghasemi
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario, Canada
| | - Denys deCatanzaro
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario, Canada
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10
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Greville LJ, Pollock T, Salter JC, Faure PA, deCatanzaro D. Progesterone transfer among cohabitating female big brown bats (Eptesicus fuscus). Gen Comp Endocrinol 2017; 247:199-204. [PMID: 28185935 DOI: 10.1016/j.ygcen.2017.02.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 02/02/2017] [Accepted: 02/05/2017] [Indexed: 01/11/2023]
Abstract
Experiments using female mice and bats have demonstrated that tritium-labeled 17β-estradiol (3H-E2) can be absorbed via cutaneous and intranasal routes and distributed to reproductive and neural tissues. Radioactivity has also been measured in tissues of untreated females after 48h cohabitation with 3H-E2 injected males. The present study was designed to quantify steroid transfer among female bats. Radioactive quantification via liquid scintillation counting revealed absorption of tritium-labeled progesterone (3H-P4) in adult females 1h after cutaneous and intranasal application (10μCi). Subsequently, pairs of mature females were each housed for 48h with a single mature female that had been administered 3H-P4 (50μCi) via intraperitoneal injection. Radioactivity was observed in all collected tissues of all non-injected females at levels significantly greater than the control group. Following the same paradigm, radioactivity was not observed in the tissues of untreated female bats that were housed with stimulus females treated with 3H-E2 (50μCi). Enzyme immunoassays revealed measurable levels of unconjugated progesterone and estradiol in the urine of female bats, suggesting urine as a vector for steroid transfer. Given that bats of this species live in predominantly female roosts in very close contact, progesterone transfer among individuals is likely to occur in natural roosts.
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Affiliation(s)
- Lucas J Greville
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - Tyler Pollock
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - Joseph C Salter
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - Paul A Faure
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - Denys deCatanzaro
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario L8S 4K1, Canada.
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Elliott B, Muir C, deCatanzaro D. Sources of variance within and among young men in concentrations of 17β-estradiol and testosterone in axillary perspiration. Physiol Behav 2017; 173:23-29. [PMID: 28119158 DOI: 10.1016/j.physbeh.2017.01.036] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 01/19/2017] [Accepted: 01/19/2017] [Indexed: 01/30/2023]
Abstract
The most potent estrogen, 17β-estradiol (E2), and its precursor, testosterone (T), play critical roles in mammalian reproductive processes. Evidence indicates that these steroids are present in bioactive form in the excretions of many male mammals. It has been demonstrated that small lipophilic steroids such as E2 can be absorbed by proximate females from male excretions, arriving in the uterus, brain, and other organs where there are estrogen receptors. We took repeated samples of axillary perspiration from men aged 20-30years during vigorous exercise. Both steroids were consistently measurable, with concentrations that ranged from values comparable to those in facial perspiration and urine of both men and women to values that greatly exceeded concentrations observed in any other substrate of men and women. Inter-individual variance in axillary E2 was positively correlated with the extent of intimate experience with women, as assessed by a questionnaire, but unrelated to subjective measures of stress, exercise habits, or phytoestrogen content of diet. In addition, higher levels of axillary E2 were observed in participants when samples were collected by a female (as compared to a male) experimenter. These data are concordant with an hypothesis that male excretion of sex steroids could exert pro-reproductive influences on proximate females.
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Affiliation(s)
- Brittney Elliott
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - Cameron Muir
- Department of Psychology, Centre for Neuroscience, Brock University, St. Catharines, Ontario L2S 3A1, Canada
| | - Denys deCatanzaro
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario L8S 4K1, Canada.
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deCatanzaro D, Pollock T. Absorption and distribution of estradiol from male seminal emissions during mating. J Endocrinol 2016; 231:245-257. [PMID: 27758953 PMCID: PMC5097127 DOI: 10.1530/joe-16-0247] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 10/06/2016] [Indexed: 12/20/2022]
Abstract
Estradiol-17β (E2) plays critical roles in female maturation, sexual receptivity, ovulation and fertility. In many mammals, contact with males can similarly affect these female parameters, whereas male excretions contain significant quantities of E2 We administered radiolabeled estradiol ([3H]E2) to male mice in doses representing a small fraction of their endogenous E2 These males were paired with sexually receptive females, and radioactivity was traced into the females' systems. In Experiment 1, males were given [3H]E2 at 24 and 1 h before mating. Male-to-female [3H]E2 transfer intensified with increasing numbers of intromissions and spiked in the uterus after insemination. In Experiment 2, sexually experienced young males received [3H]E2 at 72 and 24 h before mating, and all mated to ejaculation. The copulatory plug deposited in the female reproductive tract contained substantial levels of radioactivity. The uteri, other tissues and blood serum of females displayed radioactivity indicative of E2 transfer. In Experiment 3, radioactivity was observed 3 and 18 h after insemination in the females' uteri and other tissues, including parts of the brain. In Experiment 4, we observed substantial levels of radioactivity in semen as well as the copulatory plugs retrieved from the females after mating. Transferred E2 could directly affect abundant estrogen receptors in the female reproductive tract without potential metabolism by the liver. Sexually transferred E2 may facilitate uterine preparation for blastocyst implantation. These data converge with several lines of evidence indicating that male-sourced E2 can transfer to proximate females in bioactive form, contributing to various mammalian pheromonal effects.
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Affiliation(s)
- Denys deCatanzaro
- Department of PsychologyNeuroscience & Behaviour, McMaster University, Hamilton, Ontario, Canada
| | - Tyler Pollock
- Department of PsychologyNeuroscience & Behaviour, McMaster University, Hamilton, Ontario, Canada
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deCatanzaro D. Sex steroids as pheromones in mammals: the exceptional role of estradiol. Horm Behav 2015; 68:103-16. [PMID: 25125222 DOI: 10.1016/j.yhbeh.2014.08.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 07/31/2014] [Accepted: 08/04/2014] [Indexed: 12/18/2022]
Abstract
This article is part of a Special Issue (Chemosignals and Reproduction). Whether from endogenous or exogenous sources, 17β-estradiol (E2) has very powerful influences over mammalian female reproductive physiology and behavior. Given its highly lipophilic nature and low molecular mass, E2 readily enters excretions and can be absorbed from exogenous sources via nasal, cutaneous, and other modes of exposure. Indeed, systemic injection of tritiated estradiol ((3)H-E2) into a male mouse or bat has been shown to produce significant levels of radioactivity in the reproductive tissues and brain of cohabiting female conspecifics. Bioactive E2 and other steroids are naturally found in male mouse urine and other excretions, and males actively direct their urine at proximate females. Very low doses of E2 can mimic the Bruce effect (disruption of peri-implantation pregnancy by novel males), the Vandenbergh effect (early reproductive maturation induced by novel males), and male-induced estrus and ovulation. Males' capacities to induce the Bruce and Vandenbergh effects can both be diminished by manipulations that reduce their urinary E2. Uterine dynamics during the Bruce and Vandenbergh effects are consistent with the actions of E2. Collectively, these data demonstrate a critical role of male-sourced E2 in these major mammalian pheromonal effects.
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Affiliation(s)
- Denys deCatanzaro
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario L8S 4K1, Canada.
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