title: Altered androstenedione to testosterone ratios and LH concentrations during musth in the captive male Asian elephant (Elephas maximus).
abstract: Greater concentrations of androstenedione than testosterone were usually present during periods of non-musth in plasma collected weekly for various periods up to 2 years in 8 male Asian elephants (4-35 years of age). For the 6 males that exhibited musth the androstenedione/testosterone ratio shifted greatly in favour of testosterone. The severity of musth was assessed weekly using a scale of 1 to 5 for each of 8 behavioural traits including urine dribbling, temporal gland secretion and aggression. A significant correlation (P less than 0.05) was noted between plasma testosterone concentrations and the musth score value in 5 of 6 musth episodes. Brief shifts in the ratio of two androgens when testosterone predominated (n = 106) were seen during the non-musth period in 3 of the males studied continuously for 2 years. In 82% of these instances, stimuli of a sexual or aggressive nature had occurred in the preceding 48 h (chi 2, P less than 0.01). A heterologous bovine assay was used to measure LH values in plasma collected every 15 min for 12 h. Increases in testosterone concentrations followed pulsatile increases in plasma LH concentrations during 7 non-musth periods in 4 animals. Apart from pulse frequency, increases in the variables describing pulsatile LH secretion were seen in 2 strong musth and 2 mild musth episodes compared to non-musth values. A strong musth, however, was characterized by a much greater increase in pulsatile testosterone secretion than was a mild musth and which may be a function of the duration of musth.
authors.affiliation: Department of Biomedical Sciences University of Guelph, Ontario, Canada.
authors.forename: C A
authors.initials: CA
authors.lastname: Niemuller
authors.forename: R M
authors.initials: RM
authors.lastname: Liptrap
mesh_terms: D000728:Androgens / Q000097:blood*; D000735:Androstenedione / Q000097:blood; D000818:Animals; D004606:Elephants / Q000097:blood*; D007986:Luteinizing Hormone / Q000097:blood*; D008297:Male; D012636:Secretory Rate / Q000502:physiology; D012726:Sexual Behavior, Animal / Q000502:physiology*; D013739:Testosterone / Q000097:blood
chemical_list: D000728:Androgens; D013739:Testosterone; D000735:Androstenedione; D007986:Luteinizing Hormone