Glucocorticoids Modulate G-protein alpha-subunit Levels in Rat Hypothalamus

Glucocorticoids (Gc) affect neuroendocrine function of hypothalamic-pituitary-adrenal axis (HPAA), especially of the hypothalamus. Synthesis and secretion of neuronal hormones of hypothalamus are associated with G-protein-linked signalling system. Here, the regulation by Gc of the levels of several G-protein alpha-subunits in rat hypothalamus was studied with Western blot method. Results showed that Gc downregulated Galphas1, Galphas2,Galphai and Galphaq with different magnitudes, being 14.37,15.66,14.61 and 12.37 per cent, respectively. However, Gc did not affect Galphao expression. Our results provided important information for understanding how Gc alters neuroendocrine function through G-protein-linked signalling system.