Hypothalamic Control of Pituitary Function and Corpus Luteum Formation in the Rat.

Abstract

Bilateral hypothalamic lesions ventral to the ventro-medial nucleus in female rats resulted in persistent vaginal cornification in the majority of animals. Thyroid morphology and I131 uptake in obese rats with constant cornification indicated increased thyroid activity. The ovaries of those showing constant cornification contained follicles of all sizes but no corpora lutea. The interstitial tissue was not atrophic. The follicles were readily converted into corpora lutea by both human chorionic gonado-tropin and pituitary interstitial cell stimulating hormone. The interpretation is made that secretion of luteinizing factor by the pituitary may be impaired by small, bilateral hypothalamic lesions ventral to the ventro-medial nucleus.