Yamazaki M, Wakasugi C
Department of Legal Medicine, Osaka University Medical School, Japan.
Forensic Sci Int. 1994 Aug 10;67(3):155-68. doi: 10.1016/0379-0738(94)90086-8.
Postmortem changes in the drug-metabolizing enzymes in rat liver microsome were studied. Parameters investigated were: microsomal protein, NADPH-cytochrome P-450 reductase activity, NADH-cytochrome b5 reductase activity, cytochrome b5 content, cytochrome P-450 content, aminopyrine N-demethylase activity, aniline p-hydroxylase activity, p-nitroanisole O-demethylase activity, uridine diphosphate (UDP)-glucuronyl transferase activity and glutathione S-transferase activity. Nearly all the parameters based on microsomal protein decreased during autolysis and the time-dependent decrement ratios of the parameters changed by various amounts. Cytochrome b5 content decreased more rapidly than that of other components. By 36 h post mortem, levels of cytochrome b5 were not detectable. By 48 h post mortem, NADPH-cytochrome P-450 reductase activity decreased to 91%, NADH-cytochrome b5 reductase activity decreased to 94%, and cytochrome P-450 content decreased to 92% of relative activities. By 48 h post mortem, aminopyrine N-demethylase activity decreased to 87%, aniline p-hydroxylase activity decreased to 98% and p-nitroanisole O-demethylase activity decreased to 75% of relative activities. The activity of p-nitroanisole O-demethylase appeared to be more stable than that of aminopyrine N-demethylase or aniline p-hydroxylase. These results demonstrate that there are multiple forms of isozymes of the cytochrome P-450-linked monooxygenase system. Hepatic transferases showed decrease patterns different to those of monooxygenases, so UDP-glucuronyl transferase activity of approximately 32% of relative activity was detected at 48 h post mortem. Thus, UDP-glucuronyl transferase activity appeared to be more stable than the cytochrome P-450-linked monooxygenases. These results show that these activities and components would be useful as markers of postmortem time. The causes of the variety of instability of these enzyme systems are discussed.
研究了大鼠肝微粒体中药物代谢酶的死后变化。所研究的参数包括：微粒体蛋白、NADPH-细胞色素P-450还原酶活性、NADH-细胞色素b5还原酶活性、细胞色素b5含量、细胞色素P-450含量、氨基比林N-脱甲基酶活性、苯胺p-羟化酶活性、对硝基苯甲醚O-脱甲基酶活性、尿苷二磷酸（UDP）-葡萄糖醛酸转移酶活性和谷胱甘肽S-转移酶活性。几乎所有基于微粒体蛋白的参数在自溶过程中均下降，且各参数随时间的下降率变化幅度不同。细胞色素b5含量的下降速度比其他成分更快。死后36小时，细胞色素b5水平无法检测到。死后48小时，NADPH-细胞色素P-450还原酶活性降至相对活性的91%，NADH-细胞色素b5还原酶活性降至94%，细胞色素P-450含量降至92%。死后48小时，氨基比林N-脱甲基酶活性降至相对活性的87%，苯胺p-羟化酶活性降至98%，对硝基苯甲醚O-脱甲基酶活性降至75%。对硝基苯甲醚O-脱甲基酶的活性似乎比对氨基比林N-脱甲基酶或苯胺p-羟化酶更稳定。这些结果表明细胞色素P-450连接的单加氧酶系统存在多种同工酶形式。肝脏转移酶的下降模式与单加氧酶不同，因此在死后48小时检测到相对活性约为32%的UDP-葡萄糖醛酸转移酶活性。因此，UDP-葡萄糖醛酸转移酶活性似乎比细胞色素P-450连接的单加氧酶更稳定。这些结果表明这些活性和成分可作为死后时间的标志物。讨论了这些酶系统不稳定多样性的原因。
