Cholinolytic effects of 3,3-dimethylbutanol carbamate (DBC)

Abstract

3,3-Dimethylbutanol carbamate (DBC) was shown to block cholinergic responses of acetylcholine (ACh) on frog rectus abdominis muscle, guinea pig vas deferens and guinea pig ileum preparations. The blockade was reversed by washing and was non-competitive in nature. However, DBC did not block ACh responses on chick biventer cervicis preparation with concentrations up to 5.5 × 10 −3 M. In lower concentrations, DBC blocked neuromuscular transmission in the chick biventer cervicis nerve-muscle preparation, but in contrast to d-tubocurarine, it preserved completely the muscular responses to exogenously applied ACh. The neuroeffector transmission in the guinea pig nerve ileum preparation was also blocked by DBC. However, in contrast to atropine, which totally abolished responses to exogenous ACh during neuroeffector blockade, DBC preserved somewhat diminished responses to exogenous ACh. DBC (7 × 10 −6 M − 7 × 10 −5 M) incubated with minced guinea pig cerebral cortex caused a marked release of ACh. Since hemicholinium, hexamecholinium and tetrodotoxin inhibit ACh release from nerve endings, DBC does not appear to work like these compounds either.