Luteinization of ovaries and gonadotrophin and prolactin secretion in rats with posterior hypothalamic lesions.

Posterior hypothalamic lesions restricted to the mammillary body in newborn rats evoked significantly elevated serum prolactin concentrations (P < 0.05) in adult females in the afternoon of proestrous (16.00 h), while at the same time serum LH values appeared significantly depressed (P < 0.05) as compared to controls. FSH concentrations were not affected. Parallel to changes in hormonal pattern, the ovaries of the lesioned animals grew to excessive dimensions due to the accumulation and persistence of numerous corpora lutea (CL) (syndrome of hyperluteinized ovaries). The results suggest that the posterior hypothalamus can regulate prolactin and LH secretion and that the fate of CL is associated with a quantitative ratio in the circulation of at least two hormones, prolactin and LH.