肝性脑病大白鼠脑内脑肠肽受体的研究

An experimental study on brain-gut peptide receptorsin brains of rats with hepatic encephalopathy

作者应用放射受体分析法对肝性脑病（ＨＥ）及对照大白鼠脑粗制突触体（Ｐ＿２）膜的生长抑素（ＳＳ）和血管活性肠肽（ＶＩＰ）受体的结合特性进行测定，放射配基用￣（１２５）Ｉ－ＳＳ和￣（１２５）Ｉ－ＶＩＰ，实验数据用Ｓｃａｔｃｈａｒｄ作图法分析。结果：ＨＥ及对照鼠脑Ｐ＿２膜ＳＳ受体的Ｂｍａｘ值分别为２３８．０±１４．２及２００．Ｏ±１１．３ｆｍｏｌ／ｍｇ蛋白质，Ｋｄ值分别为３．９９±０．２２及３．８９±０．３４ｎＭ；其ＶＩＰ受体的Ｂｍａｘ值分别为９．５６±０．２９及１０．９２±０．４４ｆｍｏｌ／ｍｇ蛋白质，Ｋｄ值分别为０．２８±０．０１及０．２９±０．０１ｎＭ。分析表明：ＨＥ较对照鼠脑Ｐ＿２膜的ＳＳ受体结合位点数量增加（Ｐ＜０．００５），ＶＩＰ受体结合位点数量减少（Ｐ＜０．００２），两钟受体的亲和力均无显著改变（Ｐ＞０．０５或０．２０）。提示脑内脑肠肽受体改变在ＨＥ发生中具有重要作用。

AbstractBy means of radioligand binding assay,two brain-gut peptide,sopotostatin(SS)and vaqoactive intesti-nal peptide(VIP),receptors in crude synaptosomalmembranes of brain were investigated in rats with hep-atic encephalopathy(HE)and in controls.In HE ratsand in controls, the maximal binding capacity(Bmax)were 238.0±14.2and 200.0±11.3 fmol/mg of pro-tein,the dissociation constant(Kd)was 3.99±0.22and 3.89±0.34 nM respectively for SS receptors,TheBmax values of VIP receptors in HE rats and in con-trols were 9.56±0.29 and 10.92±0.44 fmol/mg ofprotein, the Kd values were 0.28±0.01 and 0.29±0.02 nM,respectively,Increased Bmax values of SSreceptors(p<0.005)and decreased Bmax values ofVIP receptors(P<0.002)were observed in HE ratsas compared with those in controls,The results sug-gest that changes of brain-gut peptide receptors inbrains play a significant role in the pathogenesis ofHE.