摘要
目的：探讨门静脉α肾上腺素受体及亚型的分布及其对门脉循环的调控机制。方法：采用药理受体分析方法，结合离体和整体实验，测定α肾上腺素受体拮抗剂和激动剂应用前后；ｐＡ２，ｐＤ２，ＥＣ５０，Ｒｍａｘ和门静脉压力（ＰＶＰ）。结果：①ＮＥ浓度－收缩曲线均右移，程度为哌唑嗪（Ｐｒａ）４０倍，硝苯吡啶（Ｎｉｆ）２３１．８倍，育亨宾（Ｙｏｈ）４．２倍。②对Ｒｍａｘ的抑制率：Ｎｉｆ８９．１％，Ｐｒａ７１．２％，Ｙｏｈ４１．９％。③与门静脉α受体亲和力（ｐＡ２）：Ｐｒａ８．１９，Ｙｏｈ６．０９，Ｎｉｆ６．０２。④对ＰＶＰ影响：苯福林（Ｐｈｅ）显著升高ＰＶＰ（Ｐ＜０．０５），Ｐｒａ和Ｎｉｆ显著降低ＰＶＰ（Ｐ＜０．０１）。结论：大鼠静脉α受体亚型分布α１亚型，而α１受体亚型构成中主要以α１ａ为主。它们介导门静脉的收缩效应，调节门脉循环。
Aim: To investigate the distribution of adrenoceptor subtypes in portal vein and mechanism of adrenoceptor regulating on portal circulation Methods: According to the effect in vivo and in vitro after agonist or antagonist on NE dose response effects of preparations,the pA2,pD2,EC50,Rmax and PVP were calculated by using pharmacological methods Results: NE dose response curves were shifted to the right;Pra(40 fold),Yoh(42 fold) and Nif(231 fold);The suppression of Rmax;Pra(712%),Yoh(419%) and Nif(891%);pA2,Pra(819),Yoh(609) and Nif(602);Effect of Phe,Pra and Nif on PVP:The PVP was increased by Phe(P<001) and decreased by Pra and Nif(P<001) Conclusion: In portal vein of rat, the distribution of adrenocepter subtypes were 1 type and 1a type these receptors mediated the contraction and regulated the portal circulation
