多巴酚丁胺：通过非选择性肾上腺素能受体激动作用在离体豚鼠和人心肌中产生正性肌力作用。

Dobutamine: positive inotropy by nonselective adrenoceptor agonism in isolated guinea pig and human myocardium.

作者信息

Brown L, Näbauer M, Erdmann E

出版信息

Naunyn Schmiedebergs Arch Pharmacol. 1987 Apr;335(4):385-90. doi: 10.1007/BF00165552.

Abstract

Positive inotropic responses to dobutamine have been examined using isolated myocardium from guinea pigs und humans. The potency (EC50) of dobutamine was 1.5 X 10(-6) mol/l on guinea pig papillary muscles, 1.8 X 10(-6) mol/l on guinea pig left atria and 2.5 X 10(-6) mol/l on human papillary muscle strips. In guinea pig cardiac muscles, Schild plots for the beta 1-selective antagonist, 1-practolol, using dobutamine as agonist, had slopes of less than unity. This suggested the involvement of other receptors in the inotropic response to dobutamine. The beta 2-selective antagonist, ICI 118,551, but not the alpha 1-selective antagonist, prazosin, attenuated the dobutamine response in guinea pig papillary muscles. Both ICI 118,551 and prazosin shifted the dobutamine concentration-response curve in guinea pig left atria. The positive inotropic response to dobutamine in human papillary muscles was antagonised by l-practolol and ICI 118,551 but not by prazosin. The maximal inotropic response to dobutamine was 90% that of calcium measured in the same guinea pig papillary muscles but only 37% that of calcium in human papillary muscle strips. This reduced maximal effect of dobutamine in human myocardium is probably a disease-induced change but species variations cannot be excluded.

摘要

已使用豚鼠和人类的离体心肌研究了多巴酚丁胺的正性肌力反应。多巴酚丁胺对豚鼠乳头肌的效价（EC50）为1.5×10⁻⁶mol/L，对豚鼠左心房为1.8×10⁻⁶mol/L，对人类乳头肌条为2.5×10⁻⁶mol/L。在豚鼠心肌中，以多巴酚丁胺为激动剂时，β₁选择性拮抗剂1-普拉洛尔的希尔德图斜率小于1。这表明其他受体参与了对多巴酚丁胺的正性肌力反应。β₂选择性拮抗剂ICI 118,551可减弱豚鼠乳头肌对多巴酚丁胺的反应，而α₁选择性拮抗剂哌唑嗪则无此作用。ICI 118,551和哌唑嗪均可使豚鼠左心房的多巴酚丁胺浓度-反应曲线发生位移。人类乳头肌对多巴酚丁胺的正性肌力反应可被1-普拉洛尔和ICI 118,551拮抗，但不受哌唑嗪影响。在相同的豚鼠乳头肌中，多巴酚丁胺的最大正性肌力反应为钙的90%，但在人类乳头肌条中仅为钙的37%。多巴酚丁胺在人类心肌中最大效应降低可能是疾病引起的变化，但不能排除种属差异。