THE PHARMACOLOGICAL EFFECTS OF CADMIUM ON SKELETAL NEUROMUSCULAR-TRANSMISSION

1. Cadmium (100 mu M) blocks neuromuscular transmission by blocking pr ejunctional voltage dependent calcium channels in a competitive manner . 2. Prolonged exposure to cadmium leads to a block of neuromuscular t ransmission that is not competitive. 3. Cadmium can increase the spont aneous release of acetylcholine, this release is modified by the catio n composition of the bathing solution. 4. Cadmium may enter the nerve terminal via the voltage dependent calcium channels (the L-type calciu m channel has been implicated) and exert some of its actions intracell ularly. 5. All of the extracellular effects of cadmium can be reversed by cysteine.