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.