Effects of Arginine Vasopressin and V1 Receptor Antagonist onCerebral Vasospasm Secondary to Subarachnoid Hemorrhage:An Experimental Study

OpenAlex İngilizce

important organ that synthesizes and secretes mediators effective in vascular homeostasis.Vasoactive substances secreted from the endothelium induce both contraction and dilatation in CVS, but the balance of vasoactive substances deteriorates in favor of contraction.The most important vasoactive proteins secreted from the endothelium are endothelium-derived relaxing factor (EDRF) or nitric oxide █ INTRODUCTION C erebral vasospasm (CVS) secondary to subarachnoid hemorrhage (SAH) is a reversible contraction of the brain vessels as a result of mechanic and physiologic multifactorial stimuli.Vascular endothelium is not only a passive barrier between the tissues and blood, it is also an AIM: To examine morphological, radiological and biochemical effects of arginine vasopressin (AV) and V1 receptor antagonist on cerebral vasospasm (CVS) after subarachnoid hemorrhage (SAH) in rabbits.MATERIAL and METHODS: Forty male New Zealand white rabbits were randomly divided into four groups comprising 10 rabbits each.The groups were; 1) Control group, 2) SAH group, 3) SAH+AV group, 4) SAH+V1 antagonist group.Diameters of the basilar artery in all groups were measured on angiograms.All animals were sacrificed two days following basilar angiography and tissue samples of basilar artery were obtained under microscope immediate after craniectomy for ultrastructural and biochemical examinations. RESULTS:The artery diameters were found to be 50% and 50% at the 30 th minute in the groups 2 and 3 respectively.In group 3, CVS was 13% more in comparison with the 2 nd group.In group 4, vascular constriction was 34.5% at the 30 th minute and about 30.9% at the 300 th minute.Despite the increase in regional blood flow, AV did not provide morphological change.Histological appearance was related to vascular stenosis due to CVS.Histological outcome was the best in group 4 because of less CVS. CONCLUSION:Arginine vasopressin plays an important role in CVS.We detected morphological and radiological recovery in basilar artery, besides moderate improvement due to AV receptor antagonist in CVS.