Suppression of prostaglandin F2α and oxytocin release after inhibition of testosterone synthesis in the goat

Abstract Increased peripheral plasma concentrations of testosterone were detected in goats on days 13 and 14 of the oestrous cycle (oestrus = day 0), at the onset of luteolysis. Subcutaneous administration of spironolactone (10 mg kg −1 day −1 ) on days 10 to 19 inhibited the increases in testosterone, delayed luteolysis and suppressed plasma concentrations of 13,14-dihydro-15-ketoprostaglandin F 2α and oxytocin. These results suggest that testosterone of follicular or luteal origin, possibly via aromatisation to oestrogens, is needed to expedite luteolysis and induce oestrus in the goat.