STUDIES ON BIOCHEMISTRY OF EPIDERMIS .3. CONTENT AND SOME CHARACTERISTICS OF 5'-NUCLEOTIDASES PYROPHOSPHATASES AND PHOSPHOMONOESTERASES OF ALBINO GUINEA PIG AND RAT EPIDERMIS

[摘要] Although histochemical techniques consistently show little or no alkaline phosphatase activity in mammalian epidermis, biochemical assay of saline washings and homogenates of guinea pig and rat epidermis revealed a high level of alkaline inorganic pyrophosphatase (PPase) and 5[image]-nucleotidase (AMPase, TMPase). About 80% and 40%, respectively of alkaline PPase and 5[image] -nucleotidase are present in the interstitial compartment. Albino guinea pig epidermis also contains a relatively low level of nonspecific alkaline phosphatase and ATPase. The ratios of acid to alkaline PPase, AMPase and TMPase were 0.07, 1.2 and 3.1, respectively. About 70% and 40%, respectively of acid phosphatase and alkaline 5[image] -nucleotidase were in the supernatant fraction in homogenates of washed guinea pig epidermis.