[The effect of cadmium on neuromuscular transmission in rabbit blood vessels].

Influence of cadmium on contractions of isolated v.portae of a rabbit, elicited by transmural nerve stimulation and by exogene norepinephrine, has been studied. Low concentrations of cadmium (10(-6) mol/l) potentiated contractions of the vessels in response to transmural nerve stimulation but they did not influence the magnitude of response to norepinephrine. Higher concentrations of cadmium (10(-5) - 10(-4) mol/l) inhibited contractions of v.portae elicited by both adrenergic stimuli. The results indicate that the effect of cadmium on contractions induced by transmural nerve stimulation is realized predominantly pre-synaptically, probably by influence on homeostasis of calcium in the nerve ending. Potentiation of responses of v.portae indicates a mechanism by which ions of cadmium could contribute to the development of hypertension.