Moore R H, Dowling D A
Life Sci. 1982 Oct 11;31(15):1559-66. doi: 10.1016/0024-3205(82)90047-9.
A series of studies were conducted to determine the effects of leucine-(leu-) enkephalin and methionine-(met-) enkephalin on perfusion pressure. These experiments utilized isolated perfused femoral arterial preparations in pentobarbital-anesthetized cats. The enkephalins were administered intraarterially into the femoral artery and changes in perfusion pressure recorded. Leu-enkephalin in doses of 1 microgram to 320 micrograms produced significant dose-dependent decreases in perfusion pressure (4.0 +/- 1.3% with 1 microgram to 19.1 +/- 2.1% with 320 microgram). Similar declines in perfusion pressure (5.2 +/- 2.4% with 1 microgram to 21.7 +/- 4.1% with 320 micrograms) were observed following the administration of met-enkephalin. Pretreatment with naloxone (3 mg/kg) antagonized the effects of both enkephalins. Diphenhydramine (2 mg/kg) effectively antagonized the leu-enkephalin elicited decline in perfusion pressure but blocked the effects of met-enkephalin only at lower agonist doses. Propranolol treatment (4 mg/kg) did not alter the pressure responses to either enkephalin. The results of the study show that intraarterially administered enkephalins exert a vasodilatory effect on vasculature in skeletal muscle which may be direct, indirect or both. The differential antagonism of the effects of the two enkephalins suggest that the two opioids act through different receptors or multiple receptors.
进行了一系列研究以确定亮氨酸 - 脑啡肽（leu - 脑啡肽）和甲硫氨酸 - 脑啡肽（met - 脑啡肽）对灌注压的影响。这些实验采用了戊巴比妥麻醉猫的离体灌注股动脉标本。将脑啡肽经动脉内注入股动脉，并记录灌注压的变化。剂量为1微克至320微克的亮氨酸 - 脑啡肽可使灌注压产生显著的剂量依赖性降低（1微克时为4.0±1.3%，320微克时为19.1±2.1%）。给予甲硫氨酸 - 脑啡肽后观察到类似的灌注压下降（1微克时为5.2±2.4%，320微克时为21.7±4.1%）。用纳洛酮（3毫克/千克）预处理可拮抗两种脑啡肽的作用。苯海拉明（2毫克/千克）可有效拮抗亮氨酸 - 脑啡肽引起的灌注压下降，但仅在较低激动剂剂量时阻断甲硫氨酸 - 脑啡肽的作用。普萘洛尔治疗（4毫克/千克）并未改变对任何一种脑啡肽的压力反应。研究结果表明，经动脉内给予的脑啡肽对骨骼肌血管系统具有血管舒张作用，其作用可能是直接的、间接的或两者兼有。两种脑啡肽作用的差异拮抗表明这两种阿片类药物通过不同的受体或多种受体起作用。
