EFFECT OF TESTOSTERONE UPON THE β-GLUCURONIDASE ACTIVITY OF SOME TARGET TISSUES OF THE FROG, RANA ESCULENTA

Abstract

Institute and Museum of Zoology, Faculty of Sciences, University of Naples, 80134 Naples, Italy (Received 16 March 1976) β-Glucuronidase (β-GLR) has been shown to be present in practically every animal tissue. It hydrolyses the steroid glucuronides in vitro and as such plays an important role in steroid metabolism and action in vivo. In mammalian tissues the activity level of enzymes (including β-GLR) has been interpreted as a function of the environmental presence and absence of hormone Pitot & Yatvin, 1973). It has also been postulated that lysosomal hydrolases play a role in the transformation of hormone molecules from the precursor to the functional stage. Recent observations of lela, Milone & Rastogi (1974) and Milone, Rastogi & Iela (1975) showed that the β-GLR level in the hypothalamo-hypophysial system of the frog has an annual cyclic pattern largely correlated with the cyclic changes in the plasma level of testosterone and that castration-induced