GLIAL EXTRACELLULAR-MATRIX MODULATES GAMMA-GLUTAMYL-TRANSPEPTIDASE ACTIVITY IN CULTURED BOVINE BRAIN CAPILLARY AND BOVINE AORTIC ENDOTHELIAL-CELLS

Glial extracellular matrix (ECM) elevated gamma-glutamyl transpeptidas e (gamma-GTP) activity in cultured bovine brain capillary and aortic e ndothelial cells (BBCEC, BAEC). In particular, the ECM of glial cells cultured with the conditioned medium of BAEC (BAEC CM) dramatically el evated gamma-GTP activity in BBCEC and BAEC. The ECM of glial cells cu ltured with BBCEC CM also had a marked effect. The ECM of 3T3 cells cu ltured with BAEC CM, and the ECM of glial cells cultured with 3T3 CM h ad no effect. Glial CM had no effect on gamma-GTP activity in BBCEC an d BAEC. These findings indicate that gamma-GTP activity in endothelial cells (EC) is modulated by glial ECM, and that the factor of ECM that affects gamma-GTP activity in EC arises from the interaction between glial cells and EC.