QUANTITATIVE HISTOCHEMISTRY OF HUMAN SKIN

Abstract

The enzymes, lactic de-hydrogenase (LDH), malic dehydrogenase (MDH), aldolase, glucose-6-phosphate dehydrogenase (G6PDH) and acid phosphatase were measured with 0.5 to 5 [mu]g of human epidermis, dermis, hair follicles, sweat glands and sebaceous glands. The standard deviation of replicate analyses of the same homogenate is less than 10% of the mean for all reported enzymes. Replicate homogenates of the same strip of human skin show more variance. The pH optima, the effects of certain activators, the effect of temperature and time of incubation, the effect of homogenate concentration on the activity of the 5 enzymes are reported. Of the activity of MDH, G6PDH, aldolase and acid phosphatase 75-90% is present in the supernatants after 10 minutes centrifugation at 1450 g. Only 30-50% of LDH activity is present in supernatants after such centrifugation. All 5 enzymes withstand freezing, drying and storage up to 3 months at -20[degree]C. There are striking quantitative differences between epidermis and dermis in the various skin appendages. The epidermis and epidermal appendages are highly active, more active than expected on the basis of previous manometric data.