METABOLISM OF GLYCOGEN IN THE SKIN AND THE EFFECT OF X-RAYS

[摘要] Chemically pure glycogen was isolated from dog skin. The amount of glycogen in the skin is only 1/10 to 1/3 of the amounts previously reported. After perfusion of surviving isolated dog skin with C14-labeled glucose chemically pure radioactive glycogen was recovered. De novo biosynthesis of glycogen in the skin was demonstrated and it was shown that this is a rapid and continuous process. Phosphorylase and UDPG glycogen synthetase activities were demonstrated in the skin. Main precursor of cutaneous glycogen synthesis is uridine diphosphate glucose. X-ray irradiation causes an increase of glucose incorporation into glycogen. This seems to be due to a dysbalance of synthetic and degradative enzyme activities. Epidermis and corium seem to participate equally in glycogen metabolism. Glycogen accumulation in growing hair is preceded by a long period of increased glucose incorporation into glycogen. When the glycogen content is high, the rate of glucose uptake is no longer accelerated.