Histochemical Demonstration of Phosphorylase a, Phosphorylase b and Phosphorylase Kinase in Normal Human Skin

Abstract

By the use of the theoretical control procedure, the localization of phosphorylase a, phosphorylase b and phosphorylase kinase was studied in biopsy specimens of normal human skin. In the epidermis, a weak phosphorylase a activity and moderate activities of both phosphorylase b and phosphorylase kinase were found throughout the stratum malpighii except for the stratum granulosum. The stratum corneum was completely unreactive for these three enzymatic activities. In the eccrine sweat gland, no enzymatic activities were observed in a short portion of the epidermal duct. The remainder of the duct and the secretory portion of the gland were the most intensely reactive elements in the skin. In contrast, the secretory portion of the apocrine sweat gland was free of these enzymes. The active hair follicle had abundant phosphorylase a, phosphorylase b and phosphorylase kinase in and around the keratogeneous zone. In the quiescent follicle, the entire epithelial sac around the club hair had a moderate amount of those three enzymes.