The effect of new long-acting testosterone bucyclate ester on the spermatogenesis and endocrine function of steroid-secreting glands in male Papio hamadryas

Abstract

Effects of two (at 3 month interval) intramuscular injections of testosterone bucyclate (ТВ) in doses of 4 and 8 mg/kg b. w. were studied in adult male Papio hamadryas. Both ТВ doses suppressed spermatogenesis, but this effect abated with dose increase. Azoospermia was observed in 33% ejaculate samples after ТВ in a dose of 4 mg/kg, whereas after injection of 8 mg/kg it was found in only 6% samples. Moreover, the level of peripheral testosterone depends on ТВ dose as well. It reduces by half after injection of a lower dose and surpasses the control values by 20 to 120% after injection of 8 mg/kg. Time course of LH after injection of the androgen in both doses was characterized by a phase pattern: during the first phase (0 to 16 weeks) the levels of hormone varied, and a trend to reduction could be traced; during the second phase (weeks 16-24) the concentration of the hormone sharply increased and thus remained till the end of experiment. Prolonged exposure to long-acting ТВ may inhibit the secretion of adrenal androgen dehydroepiandrosterone and precursor of the ∆₅-pathway of steroid synthesis 17-Oxypregnelone.