Levy A D, Li Q, Alvarez Sanz M C, Rittenhouse P A, Kerr J E, Van de Kar L D
Department of Pharmacology, Stritch School of Medicine, Loyola University Chicago, Maywood 60153.
Life Sci. 1992;51(12):887-97. doi: 10.1016/0024-3205(92)90396-7.
Cocaine-induced enhancement of motor activity and extracellular dopamine concentrations exhibits sensitization upon repeated exposure. In this study, the neuroendocrine responses to cocaine were examined following cocaine pretreatment regimens which have been shown to produce behavioral sensitization. Adult male rats were injected with cocaine (15 mg/kg, IP) once daily for 14 days, followed by a dose-response challenge with cocaine (1-15 mg/kg, IP) either 18 hours or 7 days after the final pretreatment injection. Blood was collected 15 minutes following injections for radioimmunoassay of ACTH, corticosterone, prolactin, and renin. Cocaine increased plasma ACTH and corticosterone, while it decreased prolactin and renin concentrations. Pretreatment with cocaine for 2 weeks did not alter any of these endocrine responses after either the 18 hour or 7 day interval between pretreatment and challenge injections. In contrast, sensitization to the locomotor stimulant effects of cocaine was observed on the final day of pretreatment injections, and 7 days later. These data suggest that these endocrine effects of cocaine do not exhibit sensitization following repeated cocaine exposure.
可卡因诱导的运动活性增强和细胞外多巴胺浓度在反复接触后会出现敏化现象。在本研究中，在已被证明可产生行为敏化的可卡因预处理方案后，检测了对可卡因的神经内分泌反应。成年雄性大鼠每天腹腔注射一次可卡因（15毫克/千克），持续14天，然后在最后一次预处理注射后18小时或7天，用可卡因（1 - 15毫克/千克，腹腔注射）进行剂量反应挑战。注射后15分钟采集血液，用于放射免疫测定促肾上腺皮质激素、皮质酮、催乳素和肾素。可卡因增加了血浆促肾上腺皮质激素和皮质酮，同时降低了催乳素和肾素浓度。在预处理和挑战注射之间间隔18小时或7天后，用可卡因预处理2周并未改变这些内分泌反应中的任何一种。相比之下，在预处理注射的最后一天以及7天后，观察到对可卡因运动刺激作用的敏化现象。这些数据表明，反复接触可卡因后，可卡因的这些内分泌作用并未表现出敏化现象。
