NOVEL NEUROSTEROIDS FOR ALCOHOL-RELATED CONDITIONS

酗酒和滥用酒精在美国和世界各地造成了严重的健康问题。大量的努力已被用于开发治疗方法，但成功有限，复发是常见的。即使在长期戒断后，戒断症状和/或强烈的渴望也常导致复发。因此，同时对戒断症状和酒精寻求行为进行神经调节可能具有治疗作用。内源性神经活性类固醇，包括3 α -羟基-5 α -孕酮-20- 1 （3 α，5 α - thp或表异孕酮），对压力，焦虑，酒精和药物寻求行为有深远的影响。几条线索的证据表明，3alpha，5alpha-THP通过gaba能机制参与了这些行为，这些机制在调节酒精戒断，渴望和奖励方面很重要。我们实验室的初步结果表明，3alpha， 5alpha-THP及其氨基类似物（NPI-113）刺激GABA受体介导的C1-摄取，防止双花青素诱发的癫痫发作，并减少嗜酒大鼠的饮酒。其他研究人员已经证明，3alpha，5alpha-THP可以减少焦虑和攻击性，这些症状可能会导致饮酒行为。总的来说，这些观察结果表明，3 - α，5 - α - thp在调节与酒精寻求行为和戒断相关的大脑机制中起着至关重要的作用。然而，由于代谢降解，这些天然产生的神经类固醇作用时间极短（20-30分钟）。该项目的目标是建立一个神经类固醇药物开发模型，包括新化合物的合成，体外和体内筛选，药代动力学和毒理学评估以及最有希望的化合物的初步临床试验。我们最近测试了特定的氨基和氰基类似物的3 - α，5 - α - thp含有化学成分，阻断代谢位点。这些化合物具有部分激动剂活性，可调节GABAA受体介导的C1-通量，并且在减少饮酒行为方面具有较长的作用时间（4-6小时）。这些特性将为开发具有GABAA调节和抗渴望活性的新型药物提供治疗效益和理论价值。具体来说，我们计划(1)利用我们先前研究的结构信息合成新的3 α，5 α - thp的氨基和氰基类似物；(2)在体外利用大鼠大脑皮层亚细胞突触eurosome制剂中的C1-摄取测定来表征GABAA受体激动剂/拮抗剂的活性；(3)测试酒精偏好P和HAD大鼠的酒精消耗减少以及猴子的酒精强化逆转。(4)对大鼠酒精戒断症状和癫痫发作的逆转进行试验，(5)建立最有效的类似物的毒性、耐受性和药代动力学特征，(6)进行中试规模的双盲安慰剂对照临床试验，以确定最有效的类似物在人类受试者中寻求酒精行为的功效。我们预测，这一综合药物开发计划将建立一个综合筛选系统，用于发现和开发治疗性神经类固醇，以管理饮酒和戒断问题。

Alcoholism and alcohol abuse pose serious health problems in the United States and around the world. A great deal of effort has been directed toward developing therapies, but success has been limited and relapse is common. Relapse is often precipitated by withdrawal symptoms and/or intense craving, even after prolonged abstinence. Therefore, simultaneous neuromodulation of withdrawal symptoms and alcohol seeking behavior could be therapeutic. The endogenous neuroactive steroids, including 3alpha-hydroxy-5alpha-pregnan-20-one (3alpha,5alpha-THP or epiallopregnanolone), have profound effects on stress, anxiety, alcohol and drug seeking behavior. Several lines of evidence suggest that 3alpha,5alpha-THP participates in these actions through GABAergic mechanisms in brain areas that are important in the regulation of alcohol withdrawal, craving and reward. Preliminary results from our laboratories demonstrate that 3alpha, 5alpha-THP and its amino-analog (NPI-113) stimulate GABA receptor-mediated C1- uptake, protect against bicuculline-induced seizures and reduce alcohol drinking in alcohol preferring rats. Other researchers have demonstrated that 3alpha,5alpha-THP reduces anxiety and aggression, symptoms that may promote alcohol-drinking behavior. Collectively, these observations suggest a crucial role for 3alpha,5alpha-THP in the regulation of brain mechanisms that are relevant to the management of alcohol-seeking behavior and withdrawal. However, these naturally occurring neurosteroids are ultra short acting (20-30 minutes) because of metabolic degradation. The objective of this project is to develop a model for neurosteroid medication development that includes synthesis of novel compounds, in vitro and in vivo screening, pharmacokinetic and toxicological evaluation and a pilot clinical trial of the most promising compound. We have recently tested specific amino- and cyano-analogs of 3alpha,5alpha-THP containing chemical moieties that block metabolic sites. These compounds have partial agonist activity modulating GABAA receptor-mediated C1- flux and a longer duration of action (4-6 hrs) in the reduction of alcohol drinking behavior. These properties should provide therapeutic benefits and have theoretical usefulness for development of novel agents with GABAA modulating and anti-craving activity. Specifically, we plan to (1) synthesize novel amino- and cyano-analogs of 3alpha,5alpha-THP using structural information derived from our previous studies, (2) characterize GABAA receptor agonist/antagonist activities in vitro using a C1- uptake assay in subcellular synaptoneurosome preparations from rat cerebral cortices, (3) test for reduction of alcohol consumption in alcohol preferring P and HAD rats and reversal of alcohol reinforcement in monkeys, (4) test for reversal of alcohol withdrawal symptoms and seizures in rats, (5) establish toxicity, tolerance, and pharmacokinetic profiles of the most active analogs, and (6) conduct a pilot scale double-blind placebo- controlled clinical trial to determine the efficacy of the most active analog in alcohol-seeking behavior in human subjects. We predict that this comprehensive medication development program will establish an integrated screening system for the discovery and development of therapeutic neurosteroids for the management of problem alcohol drinking and withdrawal.