Studies of the enzymes of purine metabolism in skin. I. Guanase activity of rat skin.

Purine-catabolizing enzymes are widely distributed among various tissues of mammalian organisms (l-5). There are indications that, at least in the case of the white rat, some of these enzymes are also present in skin. Barry et al. (6) and, more recently, Westerfeld and Richert (5) have found xanthine oxidase in rat skin. We have confirmed this finding (7) and have further shown that adenosine deaminase and possibly guanosine deaminase are also present in the skin of this animal (8). The purpose of the present paper is to report in detail experiments on the guanase and adenase activity of rat skin extracts previously reported in preliminary studies (9).