【摘要】 用氚标记苯环立啶（[³H]-pcp）与豚鼠心房匀浆蛋白作受体结合试验。结果表明豚鼠心房具有与[³H]-PCP 相结合的部位,结合具有特异性、饱和性、可逆性和立体专一性。Scatchard 分析,豚鼠心房有两个不同亲和力的特异结合部位;高亲和力和低亲和力结合部位。两者的解离常数 K_dl和K_d2分别为12.15±0.414nmol/L 和561.23±121.36nmol/L,最大结合 B_maxl 为0.71±0.029 pmol/mg 蛋白,B_maxe 为1.047±0.099 pmol/mg 蛋白。竞争性抑制分析结果显示 PCP 受体和 sigma 受体的配基都可抑制[³H]-PCP 的结合,PCP 受体的配基的抑制作用强于 sigma 配基,而广谱阿片激动剂埃托啡（etorphine）却无抑制作用。结果提示豚鼠心房存在 PCP 受体。豚鼠右心房的冰冻切片和[³H]-PCP 进行体外受体结合放射自显影,结果显示,在心房肌层有与[³H]-PCP 特异性结合部位,且呈比较均匀的散在分布。更多还原

【Abstract】 [³H]-PCP was used in receptor binding studies on membrane preparationfrom guinea pig atria.It was found that this binding was specific,saturable,re-versible and stereoselective.Scatchard plots revealed that guinea pig atria hadtwo different affinity binding sites.The high affinity constant（Kd₁）and low af-finity constant（Kd₂）were 12.15±0.414 nmol/1 and 561.23±121.36 nmol/1,respectively;the maximum bindings(B_max)were 0.71±0.029 pmol/mg protein(B_max1)and 1.047±0.099 pmol/mg protein(B_max2),respectively.The displace-ment analysis revealed that the [³H]-PCP binding was inhibited by the ligands ofboth PCP and sigma receptors,white the inhibition of PCP ligands was larger thanof sigma ligands.Etorphine,an agonist of opioid receptors,failed to inhibit thebinding of [³H]-PCP.The results mentioned above show the existence of a specificPCP receptor in guinea pig atria.The autoradiographic analysis of guinea pig right atria was shown that therewas autoradiographic localization of [³H]-PCP on atria of guinea pig with homo-genous distribution,suggesting that the distribution of PCP receptor in atria washomogeneous relatively.更多还原