C-6 glioma growth in rats: suppression with a beta-adrenergic agonist and a phosphodiesterase inhibitor.

Rat C-6 glioma possesses a beta-adrenergic receptor which, when activated, raises intracellular levels of cyclic adenosine monophosphate (cAMP) in cultured C-6 glioma cells. The present study shows that growth of C-6 glioma is suppressed in rats treated with the beta-adrenergic agonist isoproterenol. Addition of papaverine, a cAMP phosphodiesterase inhibitor, to the treatment schedule augments this effect. Pharmacological agents that elevate intracellular cAMP levels may retard the growth of neural tumors in vivo.