Mating-associated peak in plasma testosterone concentration in wild male grey-headed flying foxes (Pteropus poliocephalus).
Plasma testosterone (T) concentrations, measured in wild bats of P. poliocephalus in Queensland in 1983-87, showed a peak during the mating season in March. Plasma androstenedione (A) concentrations changed less dramatically with season. Mean testicular concentration and total content of T and A was substantially greater in March than in regressed testes in July-October. Paired adrenal glands were heavier during February to April than during September to November. In the same wild population, throughout a single breeding season (1987), plasma T concentrations were significantly higher in mid-March than 3 weeks previously or 3 weeks later. Testicular T content rose as the breeding season progressed, being greatest during March, coinciding with the large rise in plasma T concentrations. Testicular T concentration and content were correlated significantly with plasma T concentrations. Adrenal glands contained T, but the absolute concentrations were much lower than in the testis. No significant changes in plasma, testicular or adrenal A concentrations were found as the breeding season progressed. The large increase in plasma T during the mating season appears to be due to increased testicular production.
McGuckin
M A
MA
Department of Physiology and Pharmacology, University of Queensland, St. Lucia, Australia.
Blackshaw
A W
AW
D000311:Adrenal Glands / Q000033:anatomy & histology / Q000378:metabolism; D000735:Androstenedione / Q000097:blood; D000818:Animals; D002685:Chiroptera / Q000097:blood*; D003307:Copulation / Q000502:physiology*; D008297:Male; D009929:Organ Size; D012621:Seasons; D013737:Testis / Q000378:metabolism; D013739:Testosterone / Q000032:analysis / Q000097:blood*
D013739:Testosterone; D000735:Androstenedione