Pertussis toxin decreases opiate receptor binding and adenylate inhibition in a neuroblastoma x glioma hybrid cell line.

Neuroblastoma X glioma hybrid cells NG108-15 were treated with a toxin derived from Bordetella pertussis. As compared to control cells grown in the absence of toxin, the inhibitory effects of opioid agonists upon cAMP formation were dose-dependently impaired by a non-competitive mechanism. Radioligand binding studies revealed that opioid agonist binding was dramatically reduced in toxin-treated membranes when tested in the presence of Na+/Mg++/GMP-PNP. Further, the potencies of guanine nucleotides to decrease opioid agonist binding were differentially modulated. These studies may facilitate our understanding of the mechanisms responsible for acute and chronic opiate effects.