The effect of hydrogen peroxide upon β-adrenoceptor density and function in C6 rat glioma cells

Hydrogen peroxide has been suggested to play an important role in the pathogenesis of Alzheimer fn3 fn3 s disease; [ 3H](−)CGP-12177[(−)-4-(3-t-butylamino-2-hydroxypropoxy)-[5,7, 3H] benzimidazol-2-one]; ICI 118,551, ((±)-1-[2,3-(dihydro-7-methyl-1H-inden-4-yl)oxy]-3-[(l-methylethyl)amino]-2-butanol; PBN, N-t-butyl- α-phenylnitrone; Gpp[NH]p, 5′-guanylylimidodiphosphate; LDH, lactate dehydrogenase, FBS, fetal bovine scrum; PBS, phosphate buffered saline. s disease. In the present study, the effects of hydrogen peroxide upon the functional integrity of β-adrenoceptors have been investigated in C6 glioma cells. Treatment of cells for 24 h with hydrogen peroxide in serum-free medium produced a concentration-dependent cell toxicity, seen both using cell counting and LDH release into medium as end point. There were no large nor consistent changes in either the density of cell surface β 1, or β 2-adrenoceptors, measured using the hydrophilic ligand [ 3H](−)-CGP 12177, nor in either basal, forskolin and isoprenaline-stimulated cAMP responses, following hydrogen peroxide treatment. It is concluded that the decreased adenylyl cyclase activity and responsiveness to G s stimulation found in post-mortem brain samples from Alzheimers disease autopsy cases is unlikely to be mediated by hydrogen peroxide.