Priola D V, Cao X, Anagnostelis C, Bassenge E
Department of Cell Biology and Physiology, University of New Mexico School of Medicine, Albuquerque, New Mexico 87131, USA.
Am J Physiol. 1998 Jun;274(6):H2074-84. doi: 10.1152/ajpheart.1998.274.6.H2074.
The present experiments were performed to examine the capability of the intrinsic cardiac nerves (ICN) to modify cardiac performance in the resting chronic, conscious dog. Control and cardiac-denervated dogs were instrumented for recording of left atrial (LA) and ventricular (LV) contractility, heart rate, and atrioventricular (AV) conduction time. Acetylcholine (ACh) and nicotine (Nic) were administered via an indwelling coronary artery catheter. Limited distribution from the injection site only allowed access to the LA, LV, and AV node. Both beta-blockade with timolol and cardiac denervation were used to separate direct effects of ICN stimulation from indirect (e.g., reflex) effects. ACh produced the expected negative inotropic and dromotropic changes. ICN stimulation with Nic caused large decreases in LA on but only trivial effects on the LV. We concluded that the ICN has limited effects on cardiac performance in the resting animal under minimal sympathetic drive. It is likely, however, that the ICN is capable of significantly depressing cardiac function under conditions of elevated sympathetic tone as would be encountered in exercise.
进行本实验以研究心脏固有神经（ICN）在静息慢性清醒犬中调节心脏功能的能力。对对照犬和心脏去神经支配犬进行仪器植入，以记录左心房（LA）和心室（LV）的收缩力、心率以及房室（AV）传导时间。通过留置冠状动脉导管给予乙酰胆碱（ACh）和尼古丁（Nic）。仅从注射部位的有限分布允许药物作用于LA、LV和房室结。使用噻吗洛尔进行β受体阻滞和心脏去神经支配来区分ICN刺激的直接效应与间接（如反射）效应。ACh产生了预期的负性变力性和变传导性变化。用Nic刺激ICN导致LA明显下降，但对LV仅有轻微影响。我们得出结论，在最小交感神经驱动下，ICN对静息动物的心脏功能影响有限。然而，在运动等交感神经张力升高的情况下，ICN很可能能够显著抑制心脏功能。
