DIURETIC PROTECTION FROM ALCOHOL INDUCED BRAIN DAMAGE

利尿剂可防止酒精引起的脑损伤

• 批准号: 2628725
• 负责人: MICHAEL A. COLLINS
• 金额: $ 10.5万
• 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 2000-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2628725
• 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.

成年大鼠间歇性酒精（乙醇）中毒-例如，8-12 g/kg/d，分次给药4天，或仅每日一次给药（4-6 g/kg）持续6-10天-引起脑损伤，如特定的 神经变性染色，在选定的边缘皮质区域和 嗅球 此外，器官型大鼠脑切片培养物处理 间歇性地用酒精（100-200 mM）处理6天显示出 诱导细胞毒性损伤。 潜在的机制显然不是 兴奋性毒性或神经毒性相关，因为（a）体内脑损伤 谷氨酸受体拮抗剂未显著减少，a Ca++ 通道阻断剂或一氧化氮合酶抑制剂;和（B） 海马CA区，非常容易受到癫痫发作的损害， 基本上没有受到影响。 然而，每天接受一次治疗的大鼠的大脑 结果表明，酒精中毒1周后，大鼠出现水肿，Na+、K+积累。 怀疑水肿的作用，我们检查了呋塞米的作用， 强效利尿剂和C1-转运蛋白抑制剂， 在动物癫痫模型中非突触性阻断脑细胞肿胀。 事实上，呋塞米联合治疗显著降低了酒精诱导的 皮质神经退化75- 85%，因为它阻止了大脑 水肿和电解质积聚。 此外，呋塞米完全 阻断暴露于暴露于细胞毒性的器官型大鼠脑切片培养物中的细胞毒性 偶尔会酗酒 这似乎是第一次展示 在酗酒暴露期间具有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， 我们建议在R21应用程序中探索以下通用性： 通过研究其他三种利尿剂，乙酰唑胺， 氯噻酮和托拉塞米沿着非利尿呋塞米类似物 （L-644，711）。 在目标1中， 四种药物对脑水肿和变性的神经保护作用将 在每天一次用酒精中毒的雄性大鼠中进行检查， 日期间。 同时，血浆加压素，血浆和尿液 将评估渗透压摩尔浓度，以便于解释结果。 此外，脑细胞肿胀和数量将进行体视学测量 在酒精处理的大鼠中。 在Aim II中，四名特工将 用成熟的器官型大鼠皮层/海马切片检查 培养，其中细胞毒性（LDH释放）和脑细胞 生物化学（牛磺酸释放）和形态测定（体视学）肿胀 将进行测量。 我们预计大脑的减少 体内的水肿和神经变性倾向于在体外再现， 同时防止细胞肿胀。 结果可能会 为酒精中毒的神经保护提供新的治疗方法， 可以为将来详细研究可能新颖的 间歇性酒精暴露导致脑损伤的潜在机制