Biochemical and Histochemical Studies on White, Brown, and Black Skin Regions of the Guinea Pig

The study examined the biochemical and histochemical properties of black, brown, and white skin regions in guinea pigs, focusing on melanogenesis. It found that brown skin had higher levels of ascorbic acid, ascorbic acid free radical forming special peroxidase, and net bound ascorbic acid compared to black and white skin. Brown skin also contained more succinic dehydrogenase, ascorbigen, and tyrosine. Black skin showed a high capacity to utilize ascorbic acid, while white skin had the highest protein concentration. Histochemical analysis indicated that actively growing melanin-synthesizing hair follicles had greater activity of succinic dehydrogenase and ascorbic acid-related enzymes, whereas developing hair follicles in white skin were more protein-rich.