Hayashi Y, Sumikawa K, Tashiro C, Yoshiya I
Department of Anesthesiology, Osaka University Medical School, Japan.
Anesthesiology. 1988 Jun;68(6):902-7. doi: 10.1097/00000542-198806000-00011.
The authors investigated the role of alpha 1- and beta-adrenoceptors on the induction of arrhythmias during halothane anesthesia in the dog. The arrhythmogenic doses (ADs) of various combinations of alpha 1- and beta-adrenoceptor agonists were determined in dogs (N = 105) during halothane anesthesia. Isoproterenol (ISP) and phenylephrine (PHE) administered separately failed to induce arrhythmias in doses up to 4 micrograms/kg and 200 micrograms/kg, respectively. The interaction between ISP and PHE in inducing arrhythmias showed typical hyperbolic isoboles. At a systolic pressure of 140 mmHg, the AD of ISP in the presence of PHE was significantly lower than that in the presence of angiotensin II (ANG II). At a systolic pressure of 150, 160, 170, or 180 mmHg, there was no significant difference between the AD of ISP in the presence of PHE and that in the presence of ANG II. Increasing heart rate by electrical pacing did not replace ISP in the arrhythmogenic interaction between ISP and PHE. The results indicate that both alpha 1- and beta-adrenoceptor agonists are important for producing arrhythmias during halothane anesthesia, and that these agonists synergistically interact on the heart by different mechanisms.
作者研究了α1和β肾上腺素能受体在犬氟烷麻醉期间心律失常诱发中的作用。在犬（N = 105）氟烷麻醉期间，确定了α1和β肾上腺素能受体激动剂各种组合的致心律失常剂量（ADs）。单独给予异丙肾上腺素（ISP）和去氧肾上腺素（PHE），剂量分别高达4微克/千克和200微克/千克时均未能诱发心律失常。ISP和PHE在诱发心律失常方面的相互作用呈现典型的双曲线等效线。在收缩压为140 mmHg时，PHE存在下ISP的AD显著低于血管紧张素II（ANG II）存在下的AD。在收缩压为150、160、170或180 mmHg时，PHE存在下ISP的AD与ANG II存在下的AD之间无显著差异。通过电起搏增加心率并不能在ISP与PHE的致心律失常相互作用中替代ISP。结果表明，α1和β肾上腺素能受体激动剂在氟烷麻醉期间产生心律失常方面均很重要，并且这些激动剂通过不同机制在心脏上协同相互作用。
