Parrish M D, Brannon T S, Payne A, Ayres N, Fixler D E
Department of Pediatrics, University of Texas Health Science Center, Dallas.
Dev Pharmacol Ther. 1988;11(6):328-37. doi: 10.1159/000457712.
Milrinone, a new positive inotropic agent, was evaluated and compared to isoproterenol in an immature isolated isovolumic rabbit heart model. Three age groups were studied: newborns (0-6 days), juveniles (4-6 weeks old) and adults (5-7 months old). Heart rate did not change significantly with milrinone or isoproterenol in adults or juveniles, but increased in newborns from 144 +/- 1 to 162 +/- (SEM) 6 beats/min at peak milrinone effect. Milrinone had a greater effect on the contractility (maximum positive dP/dt) of the mature hearts, with newborns increasing to 134 +/- 6% of baseline, juveniles to 154 +/- 8% and adults to 216 +/- 15%. Results were similar for isoproterenol, although the positive inotropic effect occurred over a wider dosage range for this drug. No additive effects of the two drugs were noted. We conclude, that although milrinone is a positive inotropic drug in all age groups studied, the response of the newborn heart is quantitatively much weaker than that of the adult.
米力农是一种新型正性肌力药物，在未成熟的离体等容兔心模型中对其进行了评估，并与异丙肾上腺素进行了比较。研究了三个年龄组：新生儿（0 - 6天）、幼兔（4 - 6周龄）和成年兔（5 - 7月龄）。在成年兔或幼兔中，米力农或异丙肾上腺素对心率无显著影响，但在新生儿中，米力农达到峰值效应时，心率从144±1次/分钟增加到162±（标准误）6次/分钟。米力农对成熟心脏的收缩力（最大正dp/dt）影响更大，新生儿增加到基线的134±6%，幼兔增加到154±8%，成年兔增加到216±15%。异丙肾上腺素的结果相似，尽管该药物在更宽的剂量范围内产生正性肌力作用。未观察到两种药物的相加作用。我们得出结论，尽管米力农在所有研究的年龄组中都是一种正性肌力药物，但新生儿心脏的反应在数量上比成年心脏弱得多。
