Krawczak J, Kozłowska T, Wasik-Olejnik A, Beutler A, Chodera A
Department of Pharmacology, Medical Academy, Poznań, Poland.
Pol J Pharmacol Pharm. 1988 Mar-Apr;40(2):145-54.
To explain some mechanisms of the peripheral action of dopamine experiments were carried out on anesthetized rabbits in which the blood flow in calf muscles was measured during rest and during evoked twitches, using the method of 133Xe clearance of Lassen et al.; the arterial blood pressure and ECG were simultaneously recorded. Dopamine reduced the blood flow, particularly after a muscular effort. That effect of dopamine was not blocked by the alpha- and beta-adrenoceptor antagonists phentolamine and propranolol, the dopamine receptor antagonist haloperidol, or by the agent blocking sympathetic nerve endings compound BW392C60. Only low doses of dopamine given after propranolol pretreatment caused an increase in the blood flow. Dopamine depressed the arterial blood pressure, particularly the diastolic one. Pretreatment with phentolamine and haloperidol did not antagonize that effect, while pretreatment with propranolol or BW392C60 abolished or reversed the action of dopamine. The depression by dopamine of the blood flow in an important area of skeletal muscles indicates that part of the circulating blood may be shifted to other vascular beds, e.g. to the viscero - renal one.
为了解释多巴胺外周作用的一些机制，我们对麻醉的兔子进行了实验，采用拉森等人的¹³³Xe清除法测量静息期和诱发抽搐期小腿肌肉的血流量；同时记录动脉血压和心电图。多巴胺可减少血流量，尤其是在肌肉运动后。多巴胺的这种作用不受α和β肾上腺素能受体拮抗剂酚妥拉明和普萘洛尔、多巴胺受体拮抗剂氟哌啶醇或阻断交感神经末梢的化合物BW392C60的阻断。仅在普萘洛尔预处理后给予低剂量多巴胺可使血流量增加。多巴胺可降低动脉血压，尤其是舒张压。酚妥拉明和氟哌啶醇预处理不能拮抗该作用，而普萘洛尔或BW392C60预处理可消除或逆转多巴胺的作用。多巴胺对骨骼肌重要区域血流量的抑制表明，部分循环血液可能转移至其他血管床，如内脏-肾血管床。
