LHRH incorporation in normal and denervated pineal gland, and in pineal gland of rats with constant estrous-anovulatory syndrome: a preliminary study.

Pineal gland and superior sympathetic cervical ganglia accumulated intravenously injected 3H-LHRH in an amount significantly higher than anterior and posterior hypothalamus, cerebral cortex and pituitary gland, the latter a specific target for LHRH. The prior administration of unlabelled LHRH significantly decreased the 3H-LHRH incorporation only in pineal and pituitary gland. Autoradiography showed that the radiolabel was localized at the level of the pinealocytes, with a seemingly, prevalent distribution of grains on the cellular contours. Pineal incorporation of LHRH was not significantly modified by either acute or chronic bilateral cervical ganglionectomy, although acute ganglionectomy resulted in a slight decrease in LHRH accumulation by pineal gland. Constant estrous anovulatory syndromes induced by either frontal hypothalamic deafferentation, or continuous illumination, or neonatal androgenization did not appear to modify the LHRH incorporation in either pineal gland or cervical ganglia. On the basis of these results, pineal gland is supposed to be a target organ for LHRH.