Buckwalter J B, Ruble S B, Mueller P J, Clifford P S
Departments of Anesthesiology and Physiology, Medical College of Wisconsin and Veterans Affairs Medical Center, Milwaukee, Wisconsin 53295, USA.
J Appl Physiol (1985). 1998 Nov;85(5):1649-54. doi: 10.1152/jappl.1998.85.5.1649.
The purpose of this study was to determine whether beta-adrenergic or muscarinic receptors are involved in skeletal muscle vasodilation at the onset of exercise. Mongrel dogs (n = 7) were instrumented with flow probes on both external iliac arteries and a catheter in one femoral artery. Propranolol (1 mg), atropine (500 microgram), both drugs, or saline was infused intra-arterially immediately before treadmill exercise at 3 miles/h, 0% grade. Immediate and rapid increases in iliac blood flow occurred with initiation of exercise under all conditions. Peak blood flows were not significantly different among conditions (682 +/- 35, 646 +/- 49, 637 +/- 68, and 705 +/- 50 ml/min, respectively). Although the doses of antagonists employed had no effect on heart rate or systemic blood pressure, they were adequate to abolish agonist-induced increases in iliac blood flow. Because neither propranolol nor atropine affected iliac blood flow, we conclude that activation of beta-adrenergic and muscarinic receptors is not essential for the rapid vasodilation in active skeletal muscle at the onset of exercise in dogs.
本研究的目的是确定β-肾上腺素能受体或毒蕈碱受体是否参与运动开始时骨骼肌的血管舒张。用杂种狗（n = 7），在双侧髂外动脉上安装流量探头，并在一条股动脉中插入导管。在以3英里/小时、0%坡度在跑步机上运动前，立即经动脉内注入普萘洛尔（1毫克）、阿托品（500微克）、两种药物或生理盐水。在所有条件下，运动开始时髂血流量立即快速增加。各条件下的峰值血流量无显著差异（分别为682±35、646±49、637±68和705±50毫升/分钟）。虽然所用拮抗剂剂量对心率或全身血压无影响，但足以消除激动剂诱导的髂血流量增加。由于普萘洛尔和阿托品均不影响髂血流量，我们得出结论，在狗运动开始时，β-肾上腺素能受体和毒蕈碱受体的激活对于活跃骨骼肌的快速血管舒张并非必不可少。
