Nicolaysen L C, Pan H T, Justice J B
Department of Chemistry, Emory University, Atlanta, GA 30322.
Brain Res. 1988 Jul 26;456(2):317-23. doi: 10.1016/0006-8993(88)90234-x.
Microdialysis and gas chromatography/mass spectrometry were used to determine temporal cocaine concentration profiles in the rat striatum following intraperitoneal (i.p.) cocaine injection. For a 30 mg/kg i.p. dose, cocaine reached a maximum in vivo concentration of 10.1 microM within 30 min, and then rapidly declined. A non-linear fit of a kinetic model to the experimental cocaine data gave a first-order rate constant for the appearance of cocaine in the extracellular fluid of the striatum after a 30 mg/kg dose of cocaine of 0.0304/min and a first-order rate constant of 0.0386/min for the disappearance of cocaine from the extracellular fluid. When combined with previous dopamine results for a 30 mg/kg i.p. cocaine dose, cocaine concentrations were found to be highly correlated (r = 0.963) with dopamine concentrations for the same point in time. The slope was 36.8 nM dopamine/microM cocaine and the y-intercept was 29.9 nM dopamine. Maximum dopamine and maximum cocaine concentrations were also found to be linearly related to i.p. dose of cocaine for doses of 3, 10, and 30 mg/kg.
采用微透析和气相色谱/质谱联用技术测定腹腔注射可卡因后大鼠纹状体内可卡因浓度的时间变化曲线。腹腔注射30mg/kg剂量的可卡因后，30分钟内可卡因在体内达到最大浓度10.1微摩尔/升，随后迅速下降。对实验可卡因数据进行动力学模型的非线性拟合，得出腹腔注射30mg/kg剂量可卡因后，可卡因在纹状体细胞外液中出现的一级速率常数为0.0304/分钟，从细胞外液中消失的一级速率常数为0.0386/分钟。结合先前腹腔注射30mg/kg剂量可卡因后多巴胺的结果，发现可卡因浓度与同一时间点的多巴胺浓度高度相关（r = 0.963）。斜率为36.8纳摩尔多巴胺/微摩尔可卡因，截距为29.9纳摩尔多巴胺。还发现，对于3、10和30mg/kg剂量的可卡因，最大多巴胺浓度和最大可卡因浓度与腹腔注射可卡因剂量呈线性关系。
