[Treatment of rat glioma with a beta-adrenergic agonist and a phosphodiesterase inhibitor in vivo].

Rat C 6 glioma is known to possess a beta-adrenergic receptor with which intracellular cyclic adenosine monophosphate (cAMP) levels are altered to control cell growth in vitro. In order to study the effect of beta-adrenergic agonist, isoproterenol, in growth-inhibitory action upon C 6 glioma cells, subcutaneous tumor models and meningeal gliomatisis (MG) models as a brain tumor model have been exposed to the treatment of isoproterenol. Growth of subcutaneous tumor was suppressed by the treatment of the drug, and the survival time of MG rats was prolonged by the intrathecal (i. t.) injection of isoproterenol. The addition of papaverine, phosphodiesterase inhibitor, to the treatment schedule augmented the growth-inhibitory effect of isoproterenol. Therefore, it is concluded that the survival time of the brain tumor models could be prolonged through the inhibition of the growth of C 6 glioma cells by such drugs as those which elevate intracellular cAMP levels.