RESEARCH OF THE MECHANISM OF MULTIPLE ORGAN FAILURE ASSOCIATED WITH SEPSIS-IN ASSOCIATION WITH APOPTOSIS

1999年和2000年的研究：脓毒症的发展会影响各种药物的药代动力学，异丙酚是一种静脉麻醉剂，用于脓毒症患者的镇静。为了阐明脓毒症引起的麻醉药药代动力学的改变，我们阐明了参与异丙酚代谢的肝酶。我们已经证明，细胞色素P4502B6，而不是以前报道的P4502C，是参与异丙酚代谢的主要P450亚型。其次，由于咪达唑仑的药代动力学被异丙酚抑制，P4502B6和P4502C参与了咪达唑仑的代谢。虽然异丙酚在体内外均竞争性抑制咪达唑仑的代谢，但只有P4503A4参与咪达唑仑向1‘-羟基咪达唑仑的代谢，而不涉及P4502B6或P4502C。2001年研究：为了阐明静脉麻醉药在不同条件下的药代动力学，我们建立了一种SD大鼠模型。这是一种有动脉导管和静脉导管的清醒大鼠模型，可以通过监测动脉压、血气压来观察麻醉药的效果。进一步研究目的：探讨脓毒症对大鼠外周血淋巴细胞P4503A4mRNA水平、肝脏P4503A4活性及肝细胞凋亡的影响。外周血淋巴细胞P4503A4mRNA水平与肝脏P4503A4活性呈正相关。通过比较外周血淋巴细胞P4503A4mRNA水平和肝脏P4503A4活性与脓毒症的发生发展，我们可以检测肝脏细胞凋亡是由肝脏中P450水平的改变还是外周血中P450水平的变化引起的。

Research in 1999 and 2000 : Pharmacokinetics of various drugs is affected by the development of sepsis, Propofol is an intravenous anesthetic used for sedation in patients with sepsis. To elucidate the alternation of pharmacokinetics of anesthetics by sepsis, we have elucidated the hepatic enzymes involved in the metabolism of propofol. We have shown that cytochrome P4502B6, not P4502C as previously reported, is the predominant P450 isoform involved in the metabolism of propofol using human liver microsomes, cDNA-expressed microsomes and monoclonal antibodies. Secondly, involvement of P4502B6 and P4502C in the metabolism of midazolam was examined since the pharmacokinetics of midazolam is inhibited by propofol, which was metabolized by P4502B6. Although the metabolism of midazolam was competitively inhibited by propofol both in vitro and in vivo, only P4503A4 was involved in the metabolism of midazolam to 1 '-hydroxy midazolam and P4502B6 or P4502C were not involved.Research in 2001 : To elucidate the pharmacokinetics of intravenous anesthetics in various conditions, we have established an animal model with Sprague-Dawley rats. This is an awake rat model with intraarterial and intravenous catheters, which enables to observe the effect of anesthetics with monitoring arterial pressure, blood gas tension. Sepsis model can be easily made by injecting lipopolysaccharide to this rat.Future plan : To elucidate the effect of sepsis on the levels of P4503A4mRNA in lymphocytes in peripheral blood, hepatic P4503A4 activity and apoptosis of the hepatic cells. The level of P4503A4mRNA in lymphocytes in peripheral blood is correlated with the P4503A4 activity in the liver. By comparing the level of P4503A4mRNA in lymphocytes in peripheral blood and the P4503A4 activity in the liver with the development of sepsis, we can detect whether apoptosis in the liver is induced by alteration in the P450 levels in the liver or P450 in the peripheral blood.