EFFECT OF VASOPRESSIN ON DELAYED NEURONAL DAMAGE IN HIPPOCAMPUS FOLLOWING CEREBRAL ISCHEMIA AND REPERFUSION IN GERBILS

AVP was involved in the pathopysiologic process of DND in hippocampus following cerbral ischemia and reprfusion and its mechanism might be through the change of intracellular action mediated by specific AVP receptor to lead to Ca inos over-load of neuron and inhibit the Na+K^+-ATPase activity, thereby to exacerbate the D ND in hippocampus.

Abstract

Mongolian gerbils were used as delayed neuronal damage (DND) animal models.At the end of 15 minute cerebral ischermia and at various reperfusion time ranging from 1 to 96 hours,the content of water and arginine vasopressin (AVP) in the CA1 sector of hippocampus were measured by the specific gravity method and radioimmunoassy.Furthermore,we also examined the effect of intracerebroventricular (ICV) injection of AVP,AVP antiserum on calcium,Na^+,K^+-ATP ase activity in the CA1 sector after ischemia and 96 hour reperfusion.The results showed that AVP Contents of CA1 sector of hippocampus during 6 to 96 hour recirculation,and the water content of CA1 sector during 24 to 96 hour were significantly and continuously increased.After ICV injection of AVP,the water content and calcium in CA1 sector of hippocampus at cerebral ischemia and 96 hour recirculation further increased,and the Na^+,K^+-AT-tion of AVP antiserum,the water contenr and calcium in CA1 sector were significantly decreased as compared with that of control.These suggested that AVP was involved in the pathopysiologic process of DND in hippocampus following cerbral ischemia and reprfusion.Its mechanism might be through the change of intracellular action mediated by specific AVP receptor to lead to Ca inos over-load of neuron and inhibit the Na^+,K^+-ATPase activity,thereby to exacerbate the DND in hippocampus.