Sanghvi I S, Singer G, Friedman E, Gershon S
Pharmacol Biochem Behav. 1975 Jan-Feb;3(1):81-6. doi: 10.1016/0091-3057(75)90084-2.
The effect of amphetamine and l-dopa was compared in 22-hr food- and water-deprived rats. Amphetamine produced marked anorexia, and l-dopa significantly reduced food intake at 200 mg/kg. Following pretreatment with RO 4-4602, a decarboxylase inhibitor, 100 mg/kg of l-dopa, a dose that did not significantly affect eating, produced marked anorexia. The anorectic effect of both amphetamine and l-dopa was antagonized by propranolol, a beta adrenergic antagonist. Phentolamine, an alpha-adrenergic antagonist, potentiated the anorectic effect of amphetamine and l-dopa. Haloperidol (0.1 mg/kg), a dopamine antagonist, failed to prevent the anorexia due to amphetamine but accentuated that due to l-dopa. Methysergide, a serotonin antagonist, also failed to prevent the anorexigenic effect of amphetamine. Finally, the administration of l-dopa with or without peripheral decarboxylase inhibition resulted in more than twice the increase in hypothalamic dopamine levels without significant changes in 5-HT or norepinephrine levels. The data show that the anorexigenic effect of amphetamine and l-dopa are similar and indicate a functional role for both norepinephrine and dopamine neurons in feeding behaviour in the rat.
在禁食禁水22小时的大鼠中比较了苯丙胺和左旋多巴的作用。苯丙胺产生明显的厌食，左旋多巴在200mg/kg时显著减少食物摄入量。在用脱羧酶抑制剂RO 4-4602预处理后，100mg/kg的左旋多巴（该剂量对进食无显著影响）产生了明显的厌食。β肾上腺素能拮抗剂普萘洛尔拮抗了苯丙胺和左旋多巴的厌食作用。α肾上腺素能拮抗剂酚妥拉明增强了苯丙胺和左旋多巴的厌食作用。多巴胺拮抗剂氟哌啶醇（0.1mg/kg）未能预防苯丙胺引起的厌食，但增强了左旋多巴引起的厌食。5-羟色胺拮抗剂麦角新碱也未能预防苯丙胺的致厌食作用。最后，无论有无外周脱羧酶抑制，给予左旋多巴都会使下丘脑多巴胺水平升高两倍多，而5-羟色胺或去甲肾上腺素水平无显著变化。数据表明，苯丙胺和左旋多巴的致厌食作用相似，提示去甲肾上腺素能和多巴胺能神经元在大鼠摄食行为中发挥功能性作用。
