Effects of 6 α-methyl-17-acetoxyprogesterone, 17α-ethynyl-19-nortestosterone, progesterone, and testosterone propionate on the adrenals, gonads, and bursa of fabricius of the chicken

Abstract

The effects of 6α-methyl-17-acetoxyprogesterone (6-MAP), 17α-ethynyl-19-nortestosterone, testosterone propionate (TP), and progesterone on the adrenals, gonads, and bursa of Fabricius were compared in male and female chicks, pre- and postpubertal cockerels, and capons. A daily 50-μg dose of progesterone, 6-MAP, or the testosterone analogue administered for 10 days produced no consistent effects on the adrenals, testes, or bursa of chicks. Higher levels of 6-MAP significantly inhibited adrenal but not testis weight of male chicks, while higher levels of testosterone propionate inhibited testis but not adrenal weight. Both compounds at higher levels hastened bursa regression. Adrenal size of pre- and postpubertal cockerels, but not capons, was depressed by 6-MAP. It was concluded that 6-MAP inhibition of the avian adrenal is similar to that observed in the rat. This effect varies with age.