KOSTERLITZ H W, TAYLOR D W
Br J Pharmacol Chemother. 1959 Jun;14(2):209-14. doi: 10.1111/j.1476-5381.1959.tb01385.x.
The action of morphine (0.1 to 100 mg./kg.) on the cardiac slowing produced by stimulation of the right vagus nerve varied in the four species investigated. In the guinea-pig, morphine had no inhibitory effect and in the cat the effect was small, but in the rat and the rabbit stimulation of the vagus slowed the heart much less after administration of morphine than before. Further, in the last two species morphine delayed the onset of cardiac slowing. Nalorphine, which given alone had a slight morphine-like action, partly reversed the effect of morphine.
吗啡（0.1至100毫克/千克）对刺激右侧迷走神经所引起的心脏减慢作用，在所研究的四种动物中各不相同。在豚鼠中，吗啡没有抑制作用；在猫中，作用较小；但在大鼠和兔子中，给予吗啡后刺激迷走神经使心脏减慢的程度比给药前小得多。此外，在最后这两种动物中，吗啡延迟了心脏减慢的开始。纳洛啡单独使用时有轻微的吗啡样作用，它部分地逆转了吗啡的作用。
