Short-term effect of the lesion of the organum vasculosum of the lamina terminalis on hypothalamic LH-RH and serum LH, FSH and prolactin in adult female rats.

The short-term effect of the mechanical lesion of the organum vasculosum of the lamina terminalis (OVLT) was investigated in 4-day cycling female rats. The lesions were performed on the 2nd day of diestrus, and the animals were killed by decapitation 30 h after the lesion. Serum LH, FSH and prolactin and hypothalamic LH-RH content of 3 different parts of the hypothalamus were determined with radioimmunoassay. OVLT lesion caused a significant increase in the LH-RH content of the mid-basal hypothalamus and in serum prolactin levels and a decrease in LH and FSH serum levels. The results support the view that the OVLT may play a role in the control of pituitary gonadotrophic hormone secretion.