Effect of Porcine Beta Melanocyte-Stimulating Hormone on Blood Lymphocyte Count and Serum Corticosterone Concentration of the Rabbit

Abstract

Beta MSH is known to lack lipolytic or corticotropic activity in the rat. In intact rabbits, the injection of 10-100 ng purified porcine /3-MSH not only elevated serum free fatty acid (FFA) concentration 2 hr later, but also caused a reduction in blood lymphocyte count and a marked increase in serum corticosterone concentration. The effects of 10 and 100 ng (8-MSH on blood lymphocytes, serum FFA and serum corticosterone were similar in magnitude to those produced by 10 and 100 tig oxycellulose-purified ACTH. Lipolytic assays showed the ACTH preparation to be active on rat and hamster adipose tissues at a concentration of 0.01 Mg/ml, and the /3-MSH preparation to be inactive at 10 pg/ml. In the hypophysectomized rat 0.15 ng of the ACTH preparation depleted adrenal ascorbic acid content, while 500 Mg of the /3-MSH preparation had no effect. Therefore, the /3-MSH preparation contained less than 0.03% ACTH. These data suggest that /3-MSH may possess substantial corticotropic activity in the rabbit. (Endocrinology 86: 1410(Endocrinology 86: , 1970

The Mammalian Pars Intermedia: A Review of Its Structure and Function

“…However, Kastin, Miller, González-Barcena, Hawley, Dyster-Aas, Schally, Velasco de Parra & Velasco (1971) reported that the levels of plasma cortisol remained normal after the infusion of MSH in human subjects. In experimental animals the situation is similarly confused (see Karkun, Kar & Sen, 1963), although Rudman, Del Rio, Bixler & Barnett (1970) have since demonstrated that purified /?-MSH exhibits corticotrophic activity, equal to that of ACTH, when administered to rabbits.…”

The Effect of Hypophysial Hormones and Human Chorionic Gonadotrophin (Hcg) on the Anencephalic Fetal Adrenal Cortex and on Parturition in the Human

“…As anencephalic infants had low growth hormone levels and stimulation of growth hormone production was unsuccessful with a single exception (Grumbach and Kaplan, 1973) anti because high levels of prolactin have been detected in anencephaly (Robijn, 1973), we believe that growth hormone, or MSH, is likely to be the principal additional adrenotropic factor. This hypothesis is supported by animal experiments (Lostroh, 1958;Rudman et al, 1970;Colby et a l , 1973;Piva et al, 1973).…”