Résumé
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.
Sujets)
Animaux , Rats , Allopurinol , Astrocytes , Artère carotide commune , Numération cellulaire , Survie cellulaire , Hypoxie-ischémie du cerveau , Injections péritoneales , Acide lactique , Neurones , Protein kinases , Xanthine oxidase , XanthineRésumé
PURPOSE: To evaluate neurotoxic effects induced by oxygen-radicals, which were generated by adding xanthine oxidase(XO) and hypoxanthine(HX), and protective effects of glutamate receptor antagonist such as MK-801 and 6-cyano-7-nitroquinoxaline(CNQX). METHODS: Dissociated cell cultures were prepared from cerebrum of neonatal mouse. Tissues were dissected and diced into small pieces in phosphate buffered saline and were incubated at 37degrees C. Isolated cells were resuspended in Eagle's minimum essential medium and plated poly-L-lysine coated plastic coverslips in 96 well multichambers at a cell density of 3x105 cells/well. Cells were grown in a 5% CO2/95% air atmosphere at 37degrees C. Cytotoxic effects were examined in cerebral cortical neurons cultured for 3 hours in media containing various concentration of XO and HX. The protective effects of glutamate receptor antagonist were also examined by MTT assay and neurofilament enzymeimmunoassay(EIA). Microscopic examinations were also done. RESULTS: Oxygen radicals markedly induced decrement of the cell viability of cultured mouse cerebral cortical neurons in a dose-dependent manner. Midpoint cytotoxicity value was 30mU/ml XO/0.1mM HX, when mouse cerebral cortical neurons were incubated for 3 hours with various concentrations of XO and HX. The number of cells and neurites was decreased when cerebral cortical neurons were cultured for 3 hours in a medium containing 30mU/ml XO/0.1mM HX. MK- 801 was very effective in blocking oxidant-induced neurotoxicity, while CNQX falied to show any protective effect in these cultures. CONCLUSION: It is suggested that oxygen radicals are neurotoxic, and selective N-methyl-D-aspartate antagonists such as MK-801 are very effective in protecting neurotoxicity induced by oxygen radicals in cultured cerebral cortical neurons of neonatal mouse.
Sujets)
Animaux , Souris , 6-Cyano-7-nitroquinoxaline-2,3-dion e , Hypoxie , Atmosphère , Numération cellulaire , Techniques de culture cellulaire , Survie cellulaire , Cerveau , Maléate de dizocilpine , Antagonistes des acides aminés excitateurs , Acide glutamique , Ischémie , N-Méthyl-aspartate , Neurites , Neurones , Stress oxydatif , Matières plastiques , Espèces réactives de l'oxygène , Récepteurs au glutamate , XanthineRésumé
Cor triatriatum is a rare cardiac malformation in which the left atrium is subdivided into two chambers by a fibromuscular septum, one locates posterosuperiorly, which is connects with the pulmonary veins, and the other locates anteroinferiorly connecting with the mitral valves and left ventricie. It is often lethal in children with cor triatriatum due to congestive heart faliure which develops abruptly and rapidly. So, the most important thing is early detection of the disease. We experienced a case of cor triatriatum in 20 month-old female. She had severe symptoms related to congestive heart faliure, and the conditions showed dangerous. Echocardiography was used for correct diagnosis. The patients was improved dramatically after proper surgery. So, We reported this case and review literatures briefly.