The Toxic Effects of Trialkyltin Compounds on Nerve and Muscle

The toxicity of trimethyltin chloride and triethyltin sulphate on animal tissues was assessed by their effects on isolated phrenic nerve‐diaphragm preparations. Studies by electron microscopy show that the inhibitory effects of these compounds on the muscular contractility of this tissue are associated with (a) the disruption of mitochondria and disorganisation of muscle fibres and (b) the depletion of neuromicrotubules in the axons of nerves innervating the muscle. The neurotoxie effect of triethyltin sulphate on neuromicrotubules is further substantiated by its inhibition (in a concentration‐dependent manner) of the specific colchicine‐binding activity of the crude and purified tubulin preparations derived from brain tissue. In addition, both triethyltin sulphate and trimethyltin chloride at a concentration greater than 100 μM completely prevent the normal in vitro assembly of microtubules from tubulin.