The pharmacological effects of cadmium on skeletal neuromuscular transmission.
1. Cadmium (100 microM) blocks neuromuscular transmission by blocking prejunctional voltage dependent calcium channels in a competitive manner. 2. Prolonged exposure to cadmium leads to a block of neuromuscular transmission that is not competitive. 3. Cadmium can increase the spontaneous release of acetylcholine, this release is modified by the cation composition of the bathing solution. 4. Cadmium may enter the nerve terminal via the voltage dependent calcium channels (the L-type calcium channel has been implicated) and exert some of its actions intracellularly. 5. All of the extracellular effects of cadmium can be reversed by cysteine.
Braga
M F
MF
Department of Physiology and Pharmacology, Strathclyde Institute for Drug Research, University of Strathclyde, Glasgow, Scotland.
Rowan
E G
EG
D000109:Acetylcholine / Q000502:physiology; D000818:Animals; D002104:Cadmium / Q000494:pharmacology*; D002118:Calcium / Q000502:physiology; D006801:Humans; D066298:In Vitro Techniques; D018482:Muscle, Skeletal / Q000187:drug effects / Q000294:innervation; D009469:Neuromuscular Junction / Q000187:drug effects*; D009435:Synaptic Transmission / Q000187:drug effects*
D002104:Cadmium; D000109:Acetylcholine; D002118:Calcium