Agarwal O P
Artery. 1982;10(5):368-78.
The effect of norepinephrine, the adrenergic neurotransmitter, on isolated coronary arterial strips of normal and myocardial infarcted pigs was investigated with the view to characterize the nature of adrenoceptors in this tissue. In small, as well as large, isolated coronary arterial strips of normal pigs norepinephrine produced relaxation which was found to be mediated through activation of beta 1-adrenoceptors. While alpha adrenoceptors were also found to be present in large coronary arteries, they were absent in the small coronary arteries. In isolated coronary arterial strips dissected out from pigs in which myocardial infarction was induced, norepinephrine produced contraction, its alpha-adrenergic effect. This could be due to arterial hypoxia and/or sensitization of alpha-receptors present in the coronary artery.
为了明确该组织中肾上腺素能受体的性质，研究了肾上腺素能神经递质去甲肾上腺素对正常猪和心肌梗死猪离体冠状动脉条的作用。在正常猪的小冠状动脉条和大冠状动脉条中，去甲肾上腺素均引起舒张，这一作用是通过激活β1肾上腺素能受体介导的。虽然在大冠状动脉中也发现存在α肾上腺素能受体，但在小冠状动脉中却不存在。在取自诱导心肌梗死猪的离体冠状动脉条中，去甲肾上腺素引起收缩，即其α肾上腺素能效应。这可能是由于动脉缺氧和/或冠状动脉中存在的α受体敏感性增加所致。
