[Histochemical, biochemical and microelectrophoretic studies of gamma-glutamyl transpeptidase in the central nervous system of the rat].

The activity of the enzyme gamma-glutamyltranspeptidase (GGT, E.C. 2.3.2.1) was studied in brains of Wistar rats at different stages of pre- and postnatal development. In brain homogenates the activity was lowest at day 20 of pregnancy. After birth it increased slightly up to day 10 of postnatal life, than a drastic increase could be observed until day 30, where the enzyme activity reaches a plateau, which was constant over the whole lifetime. At day 15 of pregnancy histochemical examination revealed enzyme activities in brain capillaries and the leptomeninx. No or very low activities were found in the choroid plexus and in the ependyma. The GGT activity continuously increased over the following time of pregnancy and postnatal development. At day 5 of postnatal development additionally to activities in the leptomeninx, brain capillaries, choroid plexus and ependyma the enzyme could also be observed in undifferentiated cells of the subependymal periventricular layer of the telencephalon. Microdiscelectrophoretical separation of Triton X-100 homogenate extracts of microdissected cells from the subependymal layer and the ependyma or the choroid plexus, resp., revealed only one enzyme band of GGT.