儿茶酚胺对犬心脏的变力性和变时性作用。

The inotropic and chronotropic effects of catecholamines on the dog heart.

Furnival C M, Linden R J, Snow H M

J Physiol. 1971 Apr;214(1):15-28. doi: 10.1113/jphysiol.1971.sp009416.

Abstract

The chronotropic and inotropic responses of the denervated dog heart to intravenous infusions of noradrenaline, adrenaline and isoprenaline were studied.2. The maximum rate of rise of pressure in the left ventricle of the heart, (dP/dt max) measured at a constant heart rate and mean systemic arterial pressure during each series of infusions, was used as an index of inotropic changes (Furnival, Linden & Snow, 1970).3. The order of potency of the catecholamines in producing both chronotropic and inotropic effects was isoprenaline > adrenaline > noradrenaline.4. For the same increase in heart rate produced by an infusion of a catecholamine, noradrenaline caused a greater inotropic effect than adrenaline, which in turn caused a greater increase than isoprenaline.5. The chronotropic and inotropic effects of noradrenaline were potentiated by an intravenous injection of cocaine HCl (5 mg/kg), whereas those of isoprenaline were unchanged.6. The relative difference between the responses to noradrenaline and isoprenaline was abolished by an intravenous injection of cocaine HCl.7. It is concluded that the different relative chronotropic and inotropic effects of isoprenaline and noradrenaline are due to the greater uptake of noradrenaline by sympathetic nerve endings in the sinu-atrial node than in the muscle of the left ventricle.

摘要

研究了去神经支配的犬心脏对静脉输注去甲肾上腺素、肾上腺素和异丙肾上腺素的变时性和变力性反应。
在每次输注过程中，于恒定心率和平均体动脉压下测量心脏左心室压力的最大上升速率（dP/dt max），将其用作变力性变化的指标（Furnival、Linden和Snow，1970年）。
儿茶酚胺产生变时性和变力性作用的效能顺序为异丙肾上腺素＞肾上腺素＞去甲肾上腺素。
对于因输注儿茶酚胺而导致的相同心率增加，去甲肾上腺素引起的变力性作用大于肾上腺素，而肾上腺素引起的变力性增加又大于异丙肾上腺素。
静脉注射盐酸可卡因（5毫克/千克）可增强去甲肾上腺素的变时性和变力性作用，而异丙肾上腺素的作用则无变化。
静脉注射盐酸可卡因可消除对去甲肾上腺素和异丙肾上腺素反应的相对差异。
得出的结论是，异丙肾上腺素和去甲肾上腺素不同的相对变时性和变力性作用是由于窦房结交感神经末梢对去甲肾上腺素的摄取量大于左心室肌。