[Preliminary study on the effect of endothelin on the contraction of isolated rat pulmonary artery and its mechanism].
Experiment was performed on the rings of right pulmonary artery (PA) taken from male Wistar rats. Each ring was suspended in an organ bath (37 degrees C) containing Krebs solution, gassed with 95% O2-5% CO2 (pH7.40). The changes of vascular tension were measured. The contraction of PA to endothelin (ET) (10(-9) mol/L) and the effects of 764-3 (50, 100, 200, 300 micrograms/ml as a scavenger of superoxide anion), verapamil (3 x 10(-6) mol/L) NDGA, indomethacin, atropine, phentolamine, propranolol, ketanserin tartrate and diethylcarbamazine on the ET-induced contraction were investigated. The results indicated that ET can induce a potent and sustained contraction of PA, inhibited by verapamil and 764-3, but unaffected by inhibitors of cyclooxygenase, lipoxygenase, leukotrienes systhetase or adrenergic, serotonergic, cholinergic receptors. It is suggested that the influx of extracellular Ca2+ and the production of superoxide anion might be involved in the ET-induced contraction. Arachidonate metabolism and receptors mentioned above probably didn't participate in the responses.
Zheng
W
W
Department of Physiology, Chinese Academy of Medical Sciences, Beijing.
Cai
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YN
D000818:Animals; D016232:Endothelins / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D011651:Pulmonary Artery / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar
D016232:Endothelins