FOLLICLE-STIMULATING HORMONES OF THE ANTERIOR PITUITARY OF THE SHEEP AND THE HOG

Abstract

Recently, Li, Simpson and Evans (1949) described the isolation of follicle-stimulating hormone from sheep pituitary glands. Work on the same problem with hog glands as starting material has been under way in our laboratories for several years without, however achieving complete purification of the hormone. In the case of another anterior pituitary gonadotrophin from the same two species (metakentrin, ICSH, LH) it was clearly shown that although the endocrine effects of the two were identical, they were not the same proteins but had widely different isoelectric points, molecular weights and antigenic properties (Shedlovsky, et al., 1940; Li, et al., 1940 (c), 1942; Chow, et al., 1942; Gurin, 1942). It was therefore of interest to compare hog and sheep follicle-stimulating hormones. The purpose of this communication is to furnish experimental evidence for the conclusion that here again a different protein is obtained from each of the two species although the biological effects of the two hormones are identical and they are much more alike chemically than the interstitial-cell stimulating hormones (metakentrins).