The Role of Nitric Oxide in the Changes of Blood Vessels Acetylcholine Induced Dilation in the Conditions of Hyperhomocysteinemia

Abstract

The increase of Homocysteine in blood serum, according to some authors is considered to be a prognostic marker of lethal outcome. However, this issue is not fully clarified and requires further study. We considered it expedient to experimentally investigate the role of NO in the change in vasodilatory activity of Acetylcholine in the arterioles of animals with Hyperhomocysteinemia.  To achieve this goal we found it necessary to study how the vasodilatation of normal and deendothelized segments of arterioles of control animals and animals with Hyperhomocysteinemia changed in response to Acetylcholine impact in the conditions of inhibition of Nitric Oxide Synthase (NOS) activity.  The moderate Hyperhomocysteinemia was induced in male laboratory rats by addition of L-Methionine in drinking water. For inhibition of nonselelective NOS activity L-NAME has been used. Experiments were carried out on control and deendothelised preparations of first row arterioles of gracilis muscle of rats. Received results confirmed, that Hyperhomocysteinemia  is associated with the decrease in dilation induced by Acetylcholine. Presumably, this change should be related with the disruption of arterial vasomotor reactions due to deficiency of NO and appears to be an important earlier stage in the development of vascular diseases related to Hyperhomocysteinemia.