DIURETIC PROTECTION FROM ALCOHOL INDUCED BRAIN DAMAGE

利尿剂可防止酒精引起的脑损伤

• 批准号: 2894196
• 负责人: MICHAEL A. COLLINS
• 金额: $ 10.65万
• 依托单位: LOYOLA UNIVERSITY CHICAGO
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-04-01 至 2001-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2894196
• 关键词: acetazolamide; alcoholism /alcohol abuse; benzenesulfonamide; brain edema; brain injury; brain metabolism; chemoprevention; chronic brain damage; cytotoxicity; diuretics; electrolyte balance; furosemide; laboratory rat; neural degeneration; neuropharmacologic agent; neuropharmacology; neuroprotectants; neurotoxicology; osmotic pressure; tissue /cell culture; tissue /cell preparation; urinalysis

Adult rats episodically intoxicated with alcohol (ethanol)-e.g., 8-12 g/kg/d in fractional doses for 4 days, or simply one daily dose (4-6 g/kg) for 6-10 days-incur brain damage, as revealed by a specific neurodegeneration stain, in selected limbic cortical regions and the olfactory bulbs. Also, organotypic rat brain slice cultures treated episodically with alcohol (100-200 mM) for 6 days show evidence of induced cytotoxic damage. The underlying mechanism(s) is apparently not excitotoxic or seizure-related, because (a) the brain damage in vivo was not significantly diminished by glutamate receptor antagonists, a Ca++ channel blocker, or by nitric oxide synthase inhibitors; and (b) hippocampal CA regions, which are highly vulnerable to seizure damage, were largely unaffected. However, the brains of rats treated once daily with alcohol for a week were edemic and showed Na+ and K+ accumulation. Suspecting a role for edema, we examined the effect of furosemide, a potent diuretic and inhibitor of the C1- transporter that nonsynaptically blocks brain cell swelling in animal epilepsy models. Indeed, furosemide co-treatment significantly reduced alcohol-induced cortical neurodegeneration by 75-85 percent as it prevented the brain edema and electrolyte accumulation. Furthermore, furosemide completely blocked cytotoxicity in organotypic rat brain slice cultures exposed episodically to alcohol. This appears to be the first demonstration of significant neuroprotection during binge alcohol exposure. Hypothesizing brain edema as an key early step in the neurodegeneration, we propose in this R21 application to explore the generality of neuroprotection by studying three other diuretics, acetazolamide, chlorthalidone and torsemide along with a nondiuretic furosemide analog (L-644, 711) in our in vivo/in vitro approach. In Aim 1, neuroprotection from brain edema and degeneration for four agents will be examined in male rats intoxicated once daily with alcohol for an 8 day period. Concurrently, plasma vasopressin, and plasma and urine osmolality will be assessed to facilitate interpretation of results. Also, brain cell swelling and number will be measured stereologically in the alcohol-treated rats. In Aim II, the four agents will be examined with mature organotypic rat cortical/hippocampal slice cultures, in which both cytotoxicity (LDH release) and brain cell swelling by biochemical (taurine release) and morphometric (stereology) measurements will be determined. We anticipate that reductions in brain edema and neurodegeneration in vivo will tend to be reproduced in vitro, accompanied by prevention of cell swelling. The results can potentially provide new therapeutic approaches to neuroprotection in alcoholism, and can lay the groundwork for future detailed studies on possibly novel mechanisms underlying brain damage due to episodic alcohol exposure.

成年大鼠偶尔中毒于酒精(乙醇)--例如，8-12 G/kg/d，分次剂量，连续4天，或仅每日一次(4-6次 G/kg)，持续6-10天--引起脑损伤，如一种特定的 神经变性染色，在选定的边缘皮质区域和 嗅球。此外，器官型大鼠脑片培养处理 间歇性地饮酒(100-200 mm)6天显示有证据表明 诱导的细胞毒性损伤。潜在的机制(S)显然不是 兴奋毒性或癫痫相关，因为(A)体内的脑损伤是 谷氨酸受体拮抗剂，一种钙离子，不会显著降低 通道阻滞剂或一氧化氮合酶抑制剂；以及(B) 海马CA区，这是非常容易受到癫痫损害的区域， 基本上没有受到影响。然而，每天治疗一次的大鼠的大脑 饮酒一周后出现血吸虫病，表现为Na+、K+蓄积。 由于怀疑与浮肿有关，我们检查了速尿的疗效。 有效的利尿剂和C1-转运蛋白的抑制物 在动物癫痫模型中非突触抑制脑细胞肿胀。 事实上，速尿联合治疗显著减少了酒精引起的 皮质神经变性减少75%-85%，因为它阻止了大脑 浮肿和电解质积聚。此外，速尿完全 器官型大鼠脑片培养中阻断的细胞毒作用 间歇性饮酒。这似乎是第一次展示 在酗酒期间显著的神经保护作用。 假设脑水肿是神经退化的关键早期步骤， 在此R21应用程序中，我们建议探索 通过研究其他三种利尿剂，乙酰唑胺， 氯沙利酮和托塞米以及一种非利尿性速尿类似物 (L-644,711)在我们的体内/体外方法。在目标1中， 四种药物对脑水肿和变性的神经保护作用 对每天一次酒精中毒的雄性大鼠进行8次检查 一天的时间。同时，血浆加压素、血浆和尿液 将对渗透压进行评估，以便于解释结果。 此外，脑细胞肿胀和数量也将通过体视学测量。 在酒精处理的大鼠身上。在AIM II中，这四名特工将是 成熟器官型大鼠大脑皮质/海马区切片检查 细胞毒性(LDH释放)和脑细胞 生物化学(牛磺酸释放)和形态计量学(体视学)引起的肿胀 测量结果将会确定。我们预计大脑的减少 体内的水肿和神经退行性变往往会在体外复制， 伴随着防止细胞肿胀。结果可能是潜在的 为酒精中毒的神经保护提供新的治疗方法，以及 可以为未来对可能的小说进行详细研究奠定基础 间歇性酒精暴露导致脑损伤的潜在机制。