title: A longitudinal study of LH, gonadal and adrenal steroids in four intact Asian bull elephants (Elephas maximus) and one castrate African bull (Loxodonta africana) during musth and non-musth periods.
abstract: During their annual musth cycle, adult African and Asian bull elephants have increased gonadal androgens (testosterone [T], dihydrotestosterone [DHT], androstenedione [A4]). Because musth is a physiologically and psychologically stressful time, this study was conducted to investigate whether the adrenal glands (stimulated by stress) increase production of both glucocorticoids and androgens during musth. Weekly serum samples were taken for 11-15 months from four intact adult Asian bull elephants, and from a castrate African bull elephant who exhibits musth. Testosterone, androstenediol (A5), A4, luteinizing hormone (LH), cortisol, and dehydroepiandrosterone (DHEA) were measured in each sample. In three of the four intact bulls, all hormones measured increased during musth. Adrenal androgens were strongly correlated with LH and testicular androgens, though not to cortisol. None of the hormones measured in the castrate bull increased during his musth cycles. While the significance of adrenal activity in the elephant during musth has yet to be determined, this study provides evidence that the adrenal gland actively produces both glucocorticoids and androgens during musth in the Asian elephant.
authors.affiliation: Center for Health and the Environment, University of California, One Shields Ave., Davis, CA 95616, USA.
authors.forename: Lisa
authors.initials: L
authors.lastname: Yon
authors.forename: Sumolya
authors.initials: S
authors.lastname: Kanchanapangka
authors.forename: Narongsak
authors.initials: N
authors.lastname: Chaiyabutr
authors.forename: Sompast
authors.initials: S
authors.lastname: Meepan
authors.forename: Frank Z
authors.initials: FZ
authors.lastname: Stanczyk
authors.forename: Nancy
authors.initials: N
authors.lastname: Dahl
authors.forename: Bill
authors.initials: B
authors.lastname: Lasley
mesh_terms: D000311:Adrenal Glands / Q000378:metabolism; D000374:Aggression; D000818:Animals; D004606:Elephants / Q000097:blood; D012739:Gonadal Steroid Hormones / Q000097:blood*; D008137:Longitudinal Studies; D007986:Luteinizing Hormone / Q000097:blood*; D008297:Male; D009919:Orchiectomy; D012098:Reproduction; D013256:Steroids / Q000097:blood*; D013312:Stress, Physiological / Q000097:blood
chemical_list: D012739:Gonadal Steroid Hormones; D013256:Steroids; D007986:Luteinizing Hormone