In-vitro progesterone production by ovarian interstitial cells from hypophysectomized hamsters.

Collagenase-dispersed interstitial cells from 5-day hypophysectomized hamsters produced progesterone (81 +/- 7 pg/10 000 viable cells/2 h incubation) and responded to ovine LH stimulation in vitro with a dose-dependent increase in progesterone. FSH and prolactin had no effect. The interstitial cells did not produce detectable levels of oestradiol, oestrone, androstenedione, 17 alpha-hydroxyprogesterone or 20 alpha-dihydroprogesterone although 17 alpha-hydroxyprogesterone production rose to 26 +/- 5 pg/10 000 cells/2 h in response to 25 ng LH/ml. Isoproterenol (500 ng/ml) and epinephrine (500 ng/ml) stimulated progesterone production and this response was blocked by concurrent administration of 6 x 10(-6) M-propanolol which had no effect on LH-stimulated progesterone production. Simultaneous LH and catecholamine stimulation did not produce an additive effect. Incubation in medium containing 10% serum from hypophysectomized animals did not affect progesterone production. The addition of 10(-6) M-D-ala6-LHRH to interstitial cells resulted in a significant reduction of baseline steroidogenesis. These results suggest long-term retention of functional LH receptors and integrity of the steroidogenic pathway through progesterone despite chronic gonadotrophin deprivation and may indicate a role for the interstitium in priming follicular growth following periods of anoestrus.