Vasodilatory Effect of the Dissolved Glycine locally applied on Pial Microvessels

Abstract

By the method of biomicroscopy it was shown that a single application of a dissolved glycine on the parietal region of the rat brain ("open window" technique) leads to a vasodilatation -an increase in arteriolar diameter about 1.5-2 times. There were no changes in the microcirculation when saline applied under similar conditions. It was also shown that there were no pH effects on the microvessels. For the testing of the vasodilatory effect of glycine in arteriol spastic conditions the adrenomimetic phenylephrine hydrochloride possessing the vasoconstrictor properties has been used as an agent for ischemic stroke modeling. Further work on the development of an adequate ischemic stroke models is the prospective task for the testing of antiischemic preparations. Research Article Vasodilatory Effect of the Dissolved IntroductionIn recent years, the increasing prevalence of ischemic diseases affecting the vitally important organs especially those of cardiovascular and central nervous system is observed. Ischemic brain injury is accompanied by the severe neurological disorders, such as cognitive deterioration, dysfunction of motor, verbal and other CNS functions. Stroke ranks fi rst among the causes of persistent disability. Correcting the imbalance of excitatory and inhibitory neurotransmitter systems is one of the most promising areas of neuroprotection and therapeutic target. Attention of researchers is attracted to a role of inhibitory neurotransmitter glycine in the mechanisms of acute cerebral ischemia [1]. The widespread use of the drug "Glycine" in patients with neurological disorders, as well as clinical observation of the positive therapeutic effect of the drug in ischemic stroke [2,3], suggest the existence of one or more fundamental biological mechanisms responsible for the neuroprotective effect of the amino acid at the molecular level. Since one of the important pathogenic mechanisms leading to the development of an ischemic stroke is a disturbance of blood supply to the brain, the effect of any drug that is expected to have clinical benefi t should be assessed in terms of possible normalization of microcirculation. One of the tests used for an assessment of Glycine direct vasodilatory effect is an intravital biomicroscopy of pial microvessels in a brain of laboratory rats. The fi rst studies demonstrated microcirculatory effect of glycine solution on mesenteric microvessels and on pial arterioles in laboratory rats [4][5][6]