Cytolysis of rat glioma cells in vitro by autonomic drugs.

The results of glioma chemotherapy obtained so far have been rather disappointing. New attempts have been made to kill glioma cells with autonomic drugs. Experiments were done with rat C-6 glioma cells in the cell culture. Among all cholinergic blockers tested, only the irreversible cholinergic blockers such as bromoacetylcholine (BrACh), iodoacetylcholine and alphabungarotoxin were effective to inhibit glioma cells (with 50% cytolytic doses of 6.7 x 10(-6)M, 3.0 x 10(-6)M and 7.4 x 10(-5)M respectively). It is interesting to note that the hydrolytic product of BrACh, bromoacetate, was as potent as BrACh to inhibit glioma cells. Most of the adrenergic blockers, both reversible and irreversible ones, showed no cytolytic activity on glioma cells with concentrations up to 1.0 x 10(-4)M except phentolamine and propranolol which showed weak cytolytic activities. It is interesting to note, on the other hand, that 6-hydroxydopamine (an adrenergic neuron degenerating agent) and 5,6-dihydroxytryptamine (a serotonergic neuron degenerating agent) also showed mild cytolytic effects on glioma cells with 50% cytolytic doses of 5.0 x 10(-5)M and 5.3 x 10(-5)M, respectively.