Effects of the venom of the green mamba, Dendroaspis angusticeps on skeletal muscle and neuromuscular transmission.

1 The venom of the green mamba, Dendroaspis angusticeps, was tested for effects on neuromuscular transmission and skeletal muscle contractility in isolated phrenic nerve-hemidiaphragm preparations of the rat and mouse, chick biventer cervicis muscle preparations and in aneural cultures of embryonic chick skeletal muscle. 2 The venom (10 to 40 micrograms/ml) augmented the responses to indirect but not direct stimulation. As the venom did not have anticholinesterase activity and did not increase receptor sensitivity, it is likely that the venom enhanced release of acetylcholine. 3 Higher concentrations of venom (40 to 80 micrograms/ml) inhibited acetylcholine receptor sensitivity. 4 Prolonged exposure to the higher concentrations of venom produced a failure of muscle contractility. Signs of muscle degeneration were seen in skeletal muscle cultures.