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目的：探讨苯巴比妥诱导作用对鼠肝微粒体的体外葡醛酸结合反应立体选择性的影响。方法：用空白对照微粒体和经苯巴比妥（ＰＢ）诱导的微粒体作酶源，用ＵＤＰＧＡ启动葡醛酸结合反应，ＲＰ－ＨＰＬＣ法测定温育液中底物的浓度，观察苯巴比妥诱导作用对普萘洛尔对映体葡醛酸结合反应的立体选择性的影响。结果：普萘洛尔Ｒ（＋ ）和Ｓ（－ ）两种对映体在两种鼠肝微粒体的体外孵育葡醛酸缀合代谢中，酶与底物亲和力、最大反应速度和内在清除率均表现出立体选择性。在酶与底物的亲和性和Ｃｌｉｎｔ参数方面，Ｓ（－ ）为优势对映体。诱导剂ＰＢ的处理使酶与Ｓ（－ ）对映体的亲和力和最大反应速度均显著增强，与Ｒ（＋ ）对映体的最大反应速度显著增强，但酶与Ｒ（＋ ）对映体的亲和力无显著变化，Ｓ（－ ）对映体的Ｃｌｉｎｔ值显著下降，而Ｒ（＋ ）对映体的Ｃｌｉｎｔ值则显著增大。酶源对普萘洛尔对映体的葡萄糖醛酸化清除能力以Ｓ（－ ）型为优势对映体。结论：ＰＢ的诱导使鼠肝微粒体立体选择性差异缩小，但未改变其顺序，仍以Ｓ（－ ）型对映体占优势。
OBJECTIVE: To investigate the effect of phenobarbital induction on stereoselectivity of rat liver microsomal in vitro glucuronidation. Methods: Blank control microsome and phenobarbital (PB) -induced microsomes were used as enzyme source, UDPGA-activated glucuronidation reaction, RP-HPLC method was used to determine the concentration of substrate in the incubation solution. Phenobarbital The Effect of Bitumen Induction on Stereoselectivity of Propranolol Enantioselective Glucuronidation. RESULTS: The two enantiomers of propranolol, S (-) and S (-), were incubated in vitro with glucuronide-conjugated metabolites of two murine liver microsomes. The affinity between enzyme and substrate, the maximal reaction rate and the intrinsic clearance Rate showed three-dimensional selectivity. S (-) is the dominant enantiomer in terms of enzyme-substrate affinity and Clint parameters. The treatment with PB as the inducer enhanced the affinity and the maximum reaction speed of the enantiomer of S (-) and the maximum reaction rate with the R (+) enantiomer. However, The Clint value of the S (-) enantiomer decreased significantly, while the Clint value of the R (+) enantiomer increased significantly. The glucuronidation scavenging ability of enalapril on the enantiomer of propranolol with S (-) as the dominant enantiomer. Conclusion: The induction of PB induces the reduction of stereospecificity in rat liver microsomes, but it does not change its order and still dominate the enantiomer of S (-).