ANTIPLATELET ACTIVITY OF THE VESSEL WALL IN ACUTE ISCHEMIC STROKE

M.M. Tanashyan, Z.A. Suslina, V.G. Ionova
Department of Acute Disorders of Cerebral Circulation,
Laboratory of Clinical Hemorheology and Hemostasis,
Research Institute of Neurology, Russian Academy of Medical Sciences,
Moscow, Russia

Vascular endothelium is a modulator of angiohemic interactions needed for the maintenance of hemostatic homeostasis. The general hemostatic potential of the body is determined to a considerable measure by athrombogenic and primarily by antiplatelet properties of the vessel wall. The purpose of the present work was to explore antiplatelet activity of the vessel wall in patients with ischemic strokes. 76 patients with acute ischemic stroke and 15 normal subjects were examined for platelet aggregation and the content of platelet-active prostanoids (prostacycline PGI2 and thromboxane TxA2) before and after functional tests (cuff and furosemide). In normal subjects, a remarkable antiplatelet potential was revealed both due to additional production of PGI2 by vascular endothelium and preservation of platelet reactivity and sensitivity to the antiplatelet action of endogenous PGI2. Acute ischemic stroke is marked by a substantial change in antiplatelet activity of the vessel wall which manifests as a decrease of the synthesis by endothelium of the reserve amounts of PGI2, imbalance of the vasoactive prostanoids PGI2 and TxA2 as well as by distortion of regulatory relations between these prostanoids and platelet activity. The lowering of the antiplatelet potential of the vessi wall is consequent on deficiency of its prostacycline-generating ability. The disorders in the functioning of the platelet-vescular component of hemostasis may explain some causes of pharmacotherapy failure and dictate the necessity of differentiated, including sparing, selection of the drugs with regard to a possibility ofnormalization and restoration of the antiplatelet potential of the vesselwall.

KEY WORDS: ischemic stroke, vessel wall, antiplatelet activity.

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