Enhancement of the response of hen granulosa cells to LH with norepinephrine in vitro.

1. The effect of norepinephrine (NE) on progesterone production in hen granulosa cells was examined. After 4 days of the culture, the progesterone production was stimulated by chicken LH but not by NE during a 4 hr incubation. 2. The LH-stimulation progesterone production was not affected by the presence of NE when given together with LH, but was significantly increased when the cells were precultured with NE for 2 days. 3. The effect of NE was inhibited by phentolamine, but not by propranolol. 4. The results indicate that NE may enhance the responsiveness of the hen granulosa cell to LH through alpha-adrenergic receptors.

Changes in catecholamine contents in ovarian follicular theca, progesterone contents in granulosa, and LH concentrations in peripheral plasma during the ovulatory cycle in the hen.

By the use of high-performance liquid chromatography, the content of norepinephrine (NE) and epinephrine (E) in the theca of the largest and the second largest preovulatory follicle of the ovary of the hen was found to increase from 15 h (NE) or 18 h (E) to reach a peak 9 h (NE) or 9-6 h (E) before ovulation of the largest follicle. The content of progesterone in the granulosa of these follicles and the concentration of LH in the peripheral plasma of the same hen, both of which were measured by radioimmunoassays, showed a peak 6 h before ovulation. The results suggest that the catecholamines are involved in some events occurring in both follicles some several hours before ovulation of the largest follicle during the ovulatory cycle.