Schmidt M, Imbs J L
J Cardiovasc Pharmacol. 1980 Sep-Oct;2(5):595-605. doi: 10.1097/00005344-198009000-00009.
We present an in vitro method for studying the renal effects of dopamine in the isolated rat kidney. The organ is perfused in an open circuit and can be maintained satisfactorily for up to 180 min. The responses to dopamine were studied in the presence of phenoxybenzamine (10(-5) M) and sotalol (10(-5) M) while stable renal vasoconstriction was maintained by perfusion with prostaglandine F2 alpha. Dopamine induced dose-dependent renal vasodilation with an ED50 of 2.53 X 10(-6) moles/liter, which was not modified by reserpine pretreatment. (+) Butaclamol but not (-) butaclamol shifted the dopamine dose-response curve to the right in a parallel fashion, indicating competitive antagonism. Haloperidol and sulpiride at concentrations without intrinsic effect on vascular resistance also acted as competitive inhibitors for dopamine. Calculation of empirical pA2 values yielded the following relative potencies for these antagonists: (+) butaclamol greater than haloperidol greater than sulpiride. The renal vascular dopamine receptors are tentatively classified as being of the D1 type.
我们提出了一种体外方法，用于研究多巴胺对离体大鼠肾脏的影响。该器官在开放循环中进行灌注，并且可以令人满意地维持长达180分钟。在苯氧苄胺（10⁻⁵ M）和索他洛尔（10⁻⁵ M）存在的情况下研究对多巴胺的反应，同时通过用前列腺素F2α灌注维持稳定的肾血管收缩。多巴胺诱导剂量依赖性肾血管舒张，ED50为2.53×10⁻⁶摩尔/升，利血平预处理未对其产生改变。（+）布他拉莫而非（-）布他拉莫以平行方式使多巴胺剂量反应曲线右移，表明存在竞争性拮抗作用。在对血管阻力无内在影响的浓度下，氟哌啶醇和舒必利也作为多巴胺的竞争性抑制剂起作用。计算经验性pA2值得出这些拮抗剂的以下相对效价：（+）布他拉莫＞氟哌啶醇＞舒必利。肾血管多巴胺受体初步分类为D1型。
