Berdeaux A, Ghaleh B, Dubois-Randé J L, Vigué B, Drieu La Rochelle C, Hittinger L, Giudicelli J F
Département de Pharmacologie, Faculté de Médecine Paris Sud, Le Kremlin Bicêtre, France.
Circulation. 1994 Jun;89(6):2799-808. doi: 10.1161/01.cir.89.6.2799.
The role of vascular endothelium in the control of epicardial coronary artery vasomotion during treadmill exercise remains unclear. Therefore, we examined the consequences of in vivo balloon endothelial denudation on external coronary diameter of the left circumflex artery during exercise in conscious dogs.
Seven dogs instrumented for the measurement of arterial blood pressure, external coronary artery diameter, and coronary blood flow were studied during exercise before and up to 21 days after balloon endothelial denudation of the proximal left circumflex artery. Endothelial denudation was confirmed by abolition of the epicardial coronary artery dilation induced by acetylcholine (0.3 microgram/kg IV) and reactive hyperemia. Epicardial coronary vasodilation was observed in the control state during treadmill exercise (+5.2 +/- 1.0%). In contrast, a marked vasoconstriction was observed 3 (-4.6 +/- 0.6%) and up to 6 days after endothelial denudation. Complete epicardial coronary artery dilation in response to acetylcholine and exercise was restored 9 days after endothelial denudation. In addition, epicardial coronary artery vasomotor responses to acetylcholine and treadmill exercise were closely correlated (r = .82, P < .001). Reactive dilation was not completely restored 21 days after endothelial denudation, but reactive hyperemia and exercise vasomotor responses during the 21 days follow-up were correlated (r = .70, P < .001). Vasodilation induced by nitroglycerin (1 microgram/kg IV) was reduced by 25% (P < .01) 3 days after endothelial denudation and returned to its corresponding control level 3 days later. Prazosin (50 micrograms/kg IV) significantly attenuated the exercise-induced coronary artery constriction after endothelial denudation (+1.5 +/- 1.4% versus -4.6 +/- 1.0%).
These data demonstrate that endothelium is essential for the mediation of epicardial coronary dilation during exercise and may protect these vessels against the vasoconstrictor effect of endogenous catecholamines.
在跑步机运动期间，血管内皮在控制心外膜冠状动脉血管运动中的作用仍不清楚。因此，我们在清醒犬运动期间，研究了体内球囊内皮剥脱对左旋支冠状动脉外径的影响。
对7只安装了测量动脉血压、冠状动脉外径和冠状动脉血流量仪器的犬，在左旋支冠状动脉近端球囊内皮剥脱前及剥脱后长达21天的运动期间进行研究。通过乙酰胆碱（0.3微克/千克静脉注射）诱导的心外膜冠状动脉扩张及反应性充血的消失来证实内皮剥脱。在跑步机运动的对照状态下观察到心外膜冠状动脉扩张（+5.2±1.0%）。相反，在内皮剥脱后3天（-4.6±0.6%）及长达6天观察到明显的血管收缩。内皮剥脱9天后，对乙酰胆碱和运动的完全心外膜冠状动脉扩张得以恢复。此外，心外膜冠状动脉对乙酰胆碱和跑步机运动的血管舒缩反应密切相关（r = 0.82，P < 0.001）。内皮剥脱21天后反应性扩张未完全恢复，但在21天随访期间反应性充血和运动血管舒缩反应相关（r = 0.70，P < 0.001）。内皮剥脱3天后，硝酸甘油（1微克/千克静脉注射）诱导的血管扩张降低了25%（P < 0.01），3天后恢复到相应的对照水平。哌唑嗪（50微克/千克静脉注射）在内皮剥脱后显著减轻了运动诱导的冠状动脉收缩（+1.5±1.4%对-4.6±1.0%）。
这些数据表明，内皮对于运动期间心外膜冠状动脉扩张的介导至关重要，并且可能保护这些血管免受内源性儿茶酚胺的血管收缩作用。
