摘要
α_1肾上腺素受体(α_1受体)激动引起的大鼠离体血管收缩,在主动脉可为不可逆性α_1受体拮抗剂CEC大部分阻断,而不受钙离子拮抗剂硝苯吡啶的影响;在肾动脉不受CEC阻断,却可为硝苯吡啶大部分阻断;在肠系膜动脉与门静脉则介于两者之间。竞争性α_1受体拮抗剂WB4101的pA_2值,肾动脉>肠系膜动脉>主动脉。根据已知α_1受体两种亚型的药理特征,上述结果提示大鼠血管中的α_1受体存在两种亚型,在主动脉内以α_(1b)亚型为主,在肾动脉内以α_(1a)亚型为主,在肠系膜动脉与门静脉内两种亚型的含量较为均衡。
The existence and the distribution of two subtypes of a1-adrenergic receptor were studied by the functional methods in rat blood vessels. Ring preparations of aortae, renal arteries, mesenteric arteries and portal veins were perfused in Kreb's solution containing 1 μmol / L propranolol and 0.1 μmol / L yohimbine. The effects of irreversible alkylating agent chlorethylclonidine (CEC, 50 μmol/L), competitive antagonist WB 4101 and calcium antagonist nifedipine (10 μmol/L) on concentration-contraction response curves for norepinephrine (NE) were observed. The results showed that in aortae the maximal contraction caused by NE was reduced to 23% of the control by CEC and was not influenced significantly by nifedipine, while in renal arteries, the maximal contraction caused by NE was not affected significantly by CEC and was reduced to 21% of the control by nifedipine. In mesenteric arteries and portal veins, themaximal contraction caused by NE was reduced not only by CEC to 28% and 43% of the control respectively, but also by nifedipine to 25% of the control respectively. After preincubation with CEC, nifedipine totally blocked the contractile effects of NE in all the 4 kinds of blood vessels. Besides, the order of pA2 values for WB 4101 in blocking NE contraction was renal artery > mesenteric artery > aorta. These results suggest that there are two subtypes of а1- adrenergic receptor in the rat blood vessels. Subtype аla predominates in the renal artery, subtype аlb predominates in the aorta and the content of the two subtypes relatively keeps its balance in the mesenteric artery and portal vein.
出处
《中国药理学与毒理学杂志》
CAS
CSCD
北大核心
1991年第2期122-124,共3页
Chinese Journal of Pharmacology and Toxicology
基金
国家自然科学基金编号3880393
关键词
肾上腺素受体
Α1受体
药理
a1-adrenergic receptor
blood vessel
nifedipine
