Simpson L L
J Pharmacol Exp Ther. 1978 Aug;206(2):331-8.
Single or multiple injections of d-amphetamine (10(-3)--10(0) mg/kg) were administered to rats, after which steady-state blood levels of drug were determined. After single injections of d-amphetamine, there was a linear relationship between amount of administered drug and steady-state blood level of drug. After multiple injections of d-amphetamine, steady-state blood levels of drug conformed to the equation D = Doe--kappaepsilont. An attempt was made to relate steady-state blood levels of drug to steady-state responses (e.g., increase in blood pressure or heart rate). At steady-state, amphetamine-induced pressor responses were too small to be analyzed, but tachycardic responses were easily analyzed. It was found that steady-state heart rate responses were dose related to steady-state blood levels of drug. This was true regardless of whether d-amphetamine was administered once or repeatedly. The data indicate that, when tested in rats at sub-toxic doses, d-amphetamine does not evoke tachyphylaxis in relation to heart rate responses which are measured under steady-state conditions.
给大鼠单次或多次注射右旋苯丙胺（10⁻³ - 10⁰毫克/千克），之后测定药物的稳态血药浓度。单次注射右旋苯丙胺后，给药量与药物稳态血药浓度之间呈线性关系。多次注射右旋苯丙胺后，药物稳态血药浓度符合方程D = Doe⁻κϵt。尝试将药物稳态血药浓度与稳态反应（如血压升高或心率加快）联系起来。在稳态时，苯丙胺引起的升压反应过小无法分析，但心动过速反应易于分析。发现稳态心率反应与药物稳态血药浓度呈剂量相关。无论右旋苯丙胺是单次给药还是重复给药，情况均如此。数据表明，在亚中毒剂量下对大鼠进行测试时，右旋苯丙胺不会引起与稳态条件下测量的心率反应相关的快速耐受性。
