Regulation of glutamine synthetase synthesis and activity by glucocorticoids and adrenoceptor activation in astroglial cells.

Glucocorticoids are known to induce the synthesis and activity of glutamine synthetase (GS; EC 6.3.1.2.) in astroglial cells. In the present paper, noradrenaline (NA), in itself ineffective upon GS regulation, potentiated GS activity in astroglial primary cultures in the presence of the glucocorticoid dexamethasone, the GS activity being further stimulated in the presence of glutamate (glu). Thus, adrenoceptor activation might interact with the glucocorticoid induced GS activity in astroglial primary cultures.