Purification of a Bovine Hypothalamic Factor Which ElevatesPituitary MSH Levels in Rats

Abstract

Beef hypothalamic extracts contain a substance which causes an increase in the pituitary levels of melanocyte stimulating hormone (MSH) in rats. The active substance was purified by gel filtration on Sephadex columns. Administration of 0.06 [mu]g of this purified material led to significant elevation of the pituitary MSH levels in rats. Other materials known to be present in the hypothalamus didnot increase pituitary MSH content. Findings suggest the presence in mammalian hypothalamic extracts of a specific factor which may cause an inhibition of release of MSH.