[Effect of monoiodoacetate and ouabain on cholinergic vasodilation in cat skeletal muscles]

The effects of a glycolysis blocking agent monoiodoacetate and of the sodium pump blocker ouabain, on cholinergic vasodilatation in skeletal muscle were studied. In acute experiments on cats, i. v. administration of monoionoacetate eliminated both the cholinergic vasodilation and the increase in the osmotic pressure of the venous blood. I. v. injections of ouabain also abolished the vasodilatative effect of the sympathetic chain stimulation and of intraarterial injection of acetylcholine. Ouabain had no effect on the development of a sympathetic vasoconstrictive response and the vasodilative effect caused by intraarterial injection of papaverine. The data obtained indicate that cholinergic vasodilative response is due to activation of anaerobic metabolism in skeletal muscle and that hyperosmolarity resulting from the enhanced Na+ transport is a key link between tissue metabolism and vascular tone.