Effect of Xanthine Oxidase Inhibitor on Cerebral Hypoxia-Ischemia in Neonatal Rats

PURPOSE: In order to evaluate the hypoxia-ischemia(H-I) induced neurotoxicity and the protective effect of xanthine oxidase(XO) inhibitor(allopurinol), cell number, cell viability, lactate dehydrogenase(LDH), protein synthesis(PS) and protein kinase C(PKC) activity were measured in cerebral neurons and astrocytes. METHODS: Cytotoxic effect was measured by in vitro assay at 12-72 hours after H-I on cerebral neurons and astrocytes derived from 7-day old neonatal rats which were subjected to unilateral common carotid artery occlusion and exposed to hypoxic condition for 3 hours. The protective effect of XO inhibitor was examined by the cell number, cell viability, LDH and PS on 14 days after H-I with allopurinol intraperitoneal injection 15 minutes prior to H-I. In addition, the effect of allopurinol on PKC activity in hypoxic conditions was examined in neurons. RESULTS: 72 hours from H-I, the cell numbers and viability were decreased significantly in time- dependent manner on neurons and those of astrocytes also decreased slightly, compared with control. In neonatal rats treated with H-I, the cell number, cell viability, and PS in neurons were decreased, but LDH was increased significantly compared with control. In neonatal rats pretreated with allopurinol, the cell number and viability, and PS in neurons were increased and LDH was decreased significantly compared with H-I. PKC was increased remarkably after hypoxic condition. But PKC was decreased significantly against hypoxic condition after allopurinol pretreatment. CONCLUSION: From these results, it is suggested that H-I is more toxic in neurons than astrocytes and allopurinol is very protective with increasing of PS, and decreasing of LDH and PKC in neurons from hypoxic-ischemic condition.

Effect of Glutathione on Oxidant-induced Neurotoxicity in Cultured Spinal Motor Neurons / 대한마취과학회지

BACKGROUND: Free radical reactions are a part of normal human metabolism. When produced in excess, radicals can cause tissue injury. The present study was aimed to investigate neurotoxic effect of oxygen free radicals and neuroprotective effect of antioxidant(glutathione). METHODS: Neurotixic effect of oxygen radicals was evaluated by MTT[3-(4,5-dimethylthiazol-2,5- diphenyltetrazolium bromide] assay and neurofilament enzyme-immunoassay after culturing of spinal motor neuron cell line of mouse(NSC-34). Then these cells were exposed to various concentrations of xanthine oxidase(XO) and hypoxanthine(HX). In addition, neuroprotective effect of antioxidant against oxidant-induced neurototoxicity on these cultures was examined. RESULTS: Exposure of neurons to 25mU/ml XO and 0.2mM HX for 3 hours resulted in a significant cell death and also glutathione(GSH) blocked the neurotoxicity induced by oxygen radicals in cultured mouse spinal motor neurons. CONCLUSION: From the above results, it is suggested that oxygen radicals are toxic in NSC-34. Selective antioxidants such as GSH are effective in blocking oxidant-induced neurotoxicity on these cultures.