SUBSTANCE-P RECEPTORS ON HUMAN ASTROCYTOMA-CELLS ARE LINKED TO GLYCOGEN BREAKDOWN

In this study we report that substance P stimulated [H-3]glycogen brea kdown and elevation of intracellular Ca2+ concentration in the human a strocytoma cell line UC-11MG. Both effects were dose dependent, and co mpletely blocked by CP-96,345 suggesting the involvement of an NK1 rec eptor. Our previous studies indicated that norepinephrine and histamin e stimulate glycogenolysis via cAMP and Ca2+ respectively. Combined st imulation with substance P and norepinephrine or histamine resulted in additive effects suggesting that there is no interaction between thes e neurotransmitters in regulating glycogenolysis in these cells. These results confirm that UC-11MG cells are a useful model system to inves tigate the functional role of neurotransmitter receptors in astroglial cells.