CHANGES IN ARTERIOLE REACTIVITY TO NORADRENALINE UNDER CONDITIONS OF HYPERHOMOCYSTEINEMIA.

The aim of the research was the experimental study of one of the possible mechanisms performing contractile activity of arterioles in hyperhomocysteinemic animals. Moderate hyperhomocysteinemia was induced in male rats (120-160 g., n=12) by adding L-methionine to the drinking water during 4 weeks. Control animals (n=12) administered the normal water without limitation. The experiments were performed on the isolated arterioles of first line of the rat's soft muscle (Gracilis). Reactions were studied on normal and deendothelized segments of arterioles. Increased homocysteine has been found to be associated with noradrenaline-induced vascular constriction and decreased endothelium-dependent dilatation in the arterioles of the muscle. It has been suggested that the increased reactivity of blood to noradrenaline in animals in the group of hyperhomocysteinemia must have been due to impaired endothelial nitric oxide synthesis.