Samonina G E, Karazeeva E P
Biull Eksp Biol Med. 1991 Feb;111(2):174-5.
An intravenous bolus injection of 0.1 ml alpha-endorphin (1 x 10(-8)-1 x 10(-4) g/ml) didn't change the heart rate in frogs. The parasympathetic bradycardia induced by the peripheral vagus stimulation was decreased by alpha-endorphin. This vago-inhibitory action was dose-dependent (1 x 10(-5)-1 x 10(-4) g/ml). The maximal inhibitory action was watched in 4-8 and 9-15 minutes after bolus injection of alpha-endorphin in concentration of 1 x 10(-5) and 1 x 10(-4) g/ml accordingly.
静脉推注0.1毫升α-内啡肽（1×10⁻⁸ - 1×10⁻⁴克/毫升）不会改变青蛙的心率。外周迷走神经刺激诱导的副交感神经心动过缓会被α-内啡肽降低。这种迷走抑制作用呈剂量依赖性（1×10⁻⁵ - 1×10⁻⁴克/毫升）。分别以1×10⁻⁵克/毫升和1×10⁻⁴克/毫升的浓度推注α-内啡肽后，在4 - 8分钟和9 - 15分钟观察到最大抑制作用。
