Ovarian production of progesterone and 20α-dihydroprogesterone in vitro following prostaglandin F2α induced luteolysis in the superluteinized rat

Abstract

Superluteinized rats were injected with the prostaglandin F2\g=a\(PGF2\g=a\) analogue cloprostenol to induce luteolysis. The treatment decreased progesterone production of ovarian homogenates from 8.9 \m=+-\0.5 to 4.0 \ m=+-\0.7 nmol/ovary/10 min (mean \ m=+-\sem) within 40 min. tochondrial fractions isolated from control and cloprostenol treated animals produced 4.7 \m=+-\0.4 and 2.8 \ m=+-\0.3 nmol progesterone/ovary/10 min, respectively. Thus, the PGF2\g=a\analogue treatment significantly reduced mitochondrial progesterone production. Addition of the 15 000 \m=x\ g supernatant fraction did not influence the progesterone production rates of the mitochondrial fraction. The basal progesterone secretion from quartered ovaries decreased from 1.50 \m=+-\0.15 to 0.38 \m=+-\0.05