Pituitary and plasma prolactin levels in Male rats as influenced by the pineal gland

Rendering 21-day-old male rats blind (by bilateral orbital enucleation) and anosmic (by removal of the olfactory bulbs) resulted in severely depressed body weights and anterior pituitary gland weights and in reduced pituitary levels of prolactin until the animals were 125 days of age. Pinealectomy in blind anosmic rats returned all parameters toward those in controls although body weights and absolute pituitary weights were still slightly lower (p < 0.05 vs. intact controls) than normal in the animals autopsied at 75 and 100 days of age. By 125 days of age all rats had equivalent body and organ weights and also by this time pituitary prolactin levels had returned to the levels of those found in intact and pinealectomized control animals. Only in blind anosmic rats killed at 75 days of age were plasma levels of prolactin found to be significantly depressed.