Larosa G, Armstrong P W, Forster C
Department of Medicine, St. Michael's Hospital, Toronto, ON, Canada.
Can J Physiol Pharmacol. 1994 Oct;72(10):1148-54. doi: 10.1139/y94-162.
In vitro coronary artery responsiveness to noradrenaline, phenylephrine, and BHT-920 together with functional relaxation to acetylcholine was assessed in dogs at the early onset of pacing-induced heart failure (1 week) and in dogs recovered from heart failure (3 weeks paced, followed by 4 weeks discontinued pacing). alpha-Adrenoceptor stimulation produced contractile responses that were unaltered in early congestive heart failure and recovery. Contractions to noradrenaline and BHT-920 were always less than those produced by phenylephrine. Endothelium-intact arteries demonstrated relaxations in response to noradrenaline and BHT-920, but not phenylephrine. Relaxations to noradrenaline were enhanced 24% in early heart failure and 47% following recovery from heart failure, compared with control. BHT-920 produced relaxations that were augmented 21 and 76% in early heart failure and recovery, respectively. Contractile sensitivity to noradrenaline increased 5-fold in early heart failure and was not different in recovery, compared with control. Contractile sensitivity to BHT-920 and phenylephrine was unaltered throughout. Acetylcholine produced relaxations that were increased 21% in early heart failure and 13% after recovery from congestive heart failure. Furthermore, acetylcholine sensitivity was significantly enhanced in early heart failure and recovery. The current study reveals a progressive adaptation of the coronary endothelium in congestive heart failure, possibly directed towards protection against excessive vasoconstriction due to circulating catecholamines.
在起搏诱导的心力衰竭早期（1周）的犬以及从心力衰竭中恢复的犬（起搏3周，随后停止起搏4周）中，评估了体外冠状动脉对去甲肾上腺素、苯肾上腺素和BHT - 920的反应性以及对乙酰胆碱的功能性舒张作用。α - 肾上腺素能受体刺激产生的收缩反应在早期充血性心力衰竭和恢复过程中未发生改变。对去甲肾上腺素和BHT - 920的收缩反应始终小于苯肾上腺素所产生的反应。内皮完整的动脉对去甲肾上腺素和BHT - 920表现出舒张反应，但对苯肾上腺素无反应。与对照组相比，在早期心力衰竭中对去甲肾上腺素的舒张反应增强了24%，在心力衰竭恢复后增强了47%。BHT - 920产生的舒张反应在早期心力衰竭和恢复过程中分别增强了21%和76%。与对照组相比，在早期心力衰竭中对去甲肾上腺素的收缩敏感性增加了5倍，在恢复过程中无差异。对BHT - 920和苯肾上腺素的收缩敏感性在整个过程中未发生改变。乙酰胆碱产生的舒张反应在早期心力衰竭中增加了21%，在充血性心力衰竭恢复后增加了13%。此外，在早期心力衰竭和恢复过程中乙酰胆碱敏感性显著增强。当前研究揭示了充血性心力衰竭中冠状动脉内皮的渐进性适应，可能旨在防止由于循环儿茶酚胺引起的过度血管收缩。
