Effects of Catecholamines on Isolated Canine Facial Veins

[摘要] References(12)Cited-By(6)The buccal segment of the canine facial vein which was precontracted moderately with prostaglandin F2α relaxed to different extents in response to dopamine (DA), norepinephrine (NE), epinephrine (Epi) and isoproterenol (Isp). Propranolol (10-6M) reversed the relaxation responses to contractions. In the presence of an α-adrenoceptor blockade and inhibitors of neuronal and extraneuronal uptakes, the four catecholamines relaxed the vein fully, and the order of pD2 values was Isp (8.34) > Epi (7.53) ≅ NE (7.50) >> DA (5.31). The results indicate that in the canine facial vein, β-adrenoceptors predominate over α-adrenoceptors, and the subtype of β-adrenoceptor may be the β1-type.

[学科分类] 药理学