title: Absorption and distribution of estradiol from male seminal emissions during mating.
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 E2We administered radiolabeled estradiol ([3H]E2) to male mice in doses representing a small fraction of their endogenous E2These males were paired with sexually receptive females, and radioactivity was traced into the females' systems. In Experiment 1, males were given [3H]E2at 24 and 1 h before mating. Male-to-female [3H]E2transfer intensified with increasing numbers of intromissions and spiked in the uterus after insemination. In Experiment 2, sexually experienced young males received [3H]E2at 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 E2transfer. 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 E2could directly affect abundant estrogen receptors in the female reproductive tract without potential metabolism by the liver. Sexually transferred E2may facilitate uterine preparation for blastocyst implantation. These data converge with several lines of evidence indicating that male-sourced E2can transfer to proximate females in bioactive form, contributing to various mammalian pheromonal effects.
authors.affiliation: Department of PsychologyNeuroscience & Behaviour, McMaster University, Hamilton, Ontario, Canada decatanz@mcmaster.ca.
authors.forename: Denys
authors.initials: D
authors.lastname: deCatanzaro
authors.affiliation: Department of PsychologyNeuroscience & Behaviour, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Tyler
authors.initials: T
authors.lastname: Pollock
mesh_terms: D000818:Animals; D004958:Estradiol / Q000008:administration & dosage / Q000378:metabolism* / Q000493:pharmacokinetics; D005260:Female; D008297:Male; D051379:Mice; D010675:Pheromones / Q000378:metabolism; D012098:Reproduction / Q000502:physiology; D012661:Semen / Q000378:metabolism*; D012726:Sexual Behavior, Animal / Q000502:physiology*; D014018:Tissue Distribution; D014316:Tritium; D014599:Uterus / Q000378:metabolism
chemical_list: D010675:Pheromones; D014316:Tritium; D004958:Estradiol
keywords: behaviour; estrogen; female reproduction; reproduction; uterus