• Toxicological Research
• /
• 제23권4호
• /
• pp.289-299
• /
• 2007

Lipopolysaccharide (LPS) endotoxin is an active component in the outer membrane of Gram-negative bacteria. LPS is usually used as an inflammatory animal model. During the inflammation, diarrhea and changes in plasma proteins, in hepatic and/or intestinal microsomal cytochrome P450 (CYP) isozymes, and in the renal and/or biliary excretion of drugs have been reported. Thus, in rats pretreated with lipopolysaccharide endotoxin isolated from Klebsiella pneumoniae (KPLPS rats), the absorption, distribution, metabolism, and excretion of drugs could be expected to be altered. Interestingly time-dependent effects on the hepatic CYP isozymes have been reported in KPLPS rats. Thus, in KPLPS rats, the pharmacokinetics of drugs which are mainly metabolized via CYP isozymes could be expected to be time-dependent. In this review, an attempt to explain changes in pharmacokinetics of drug reported in the literature was made in terms of CYP isozyme changes or urinary and/or biliary excretion changes in KPLPS rats.

• Archives of Pharmacal Research
• /
• 제27권7호
• /
• pp.693-712
• /
• 2004

The rats with protein-calorie malnutrition (PCM, 5％ casein diet for a period of 4-week) were reported to exhibit 60 and 80％ suppression in the hepatic microsomal cytochrome P450 (CYP) 1 A2 and CYP2C11 levels, respectively, and 40-50％ decreases in CYP2E1 and CYP3A 1/2 levels compared to control (23％ casein diet for a period of 4-week) based on Western blot analysis. In addition, Northern blot analysis showed that CYP1 A2, CYP2E1, CYP2C11, and CYP3A1/2 mRNAs decreased in the state of PCM as well. Hence, pharmacokinetic changes of the drugs in rats with PCM [especially the area under the plasma concentration-time curve from time zero to time infinity (AUC) changes of metabolite(s)] reported from literatures were tried to explain in terms of CYP isozyme changes in the rats. Otherwise, the time-averaged nonrenal clearance ($CL_{NR}$) of parent drug was compared. Pharmacokinetic changes of the drugs in other types of malnutritional state, such as kwashiorkor and marasmus, in both human and animal models were also compared. The drugs reviewed are as follows： diuretics, antibiotics, anticancer agents, antiepileptics, antiarrythmics, analgesics, xanthines, antimalarials, and miscellaneous.

• Archives of Pharmacal Research
• /
• 제27권2호
• /
• pp.232-238
• /
• 2004

Trolox is a hydrophilic analogue of vitamin E. The aim of this study was to investigate its effects on hepatic injury, especially alteration in cytochrome P450 (CYP)-dependent drug metabolism during polymicrobial sepsis. Rats were subjected to polymicrobial sepsis by cecal ligation and puncture (CLP). The rats were treated intravenously with Trolox (2.5 mg/kg) or vehicle, immediately after CLP. Serum aminotransferases and lipid peroxidation levels were markedly increased 24 h after CLP. This increase was attenuated by Trolox. Total CYP content and NADPH-P450 reductase activity decreased significantly 24 h after CLP. This decrease in CYP content was attenuated by Trolox. At 24 h after CLP, there was a significant decrease in the activity of these CYP isozymes: CYP1A1, 1A2, 2B1, and 2E1. However, Trolox differentially inhibited the decrease in CYP isozyme activity. Trolox had little effect on the decrease in CYP1A1 activity but Trolox significantly attenuated decreases in CYP1A2 and 2E1 activities. In fact, Trolox restored CYP2B1 activity to the level of activity found in control rats. Our findings suggest that Trolox reduces hepatocellular damage as indicated by abnormalities in hepatic drug-metabolizing function during sepsis. Our data also indicates that this protection is, in part, caused by decreased lipid peroxidation.

• 대한약학회:학술대회논문집
• /
• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
• /
• pp.301.2-301.2
• /
• 2002

The present study was done to determine the effect of trolox C. a hydrophilic analogue of vitamin E. on alteration in cytochrome P-450 (CYP)-dependent drug metabolism during ischemia and reperfusion. Rats were subjected to 60 min of hepatic ischemia and 5 h of reperfusion. Rats were treated intravenously with trolox C (2.5 mg/kg) or vehicle (PBS. pH 7.4), 5 min before reperfusion. Serum alanine aminotransferase and lipid peroxidation levels were markedly increased after ischemia and reperfusion. This increase was significantly suppressed by trolox C. (omitted)

• Archives of Pharmacal Research
• /
• 제26권5호
• /
• pp.394-404
• /
• 2003

Certain polycyclic aromatic hydrocarbons (PAHs) have been reported to induce cytochrome P450 (CYP) 1A1 and 1A2. In the present study, the effects of six well-known PAHs, such as benzo[a]pyrene, benz[a]anthracene, dibenz[a,h]anthracene, chrysene, benzo[k]fluorancene and benzo[b]fluorancene, on the activities of hepatic and pulmonary CYP enzymes were investigated in male ICR mice. When mice were treated intraperitoneally with 3, 10 and 30 mg/kg of individual PAHs for 3 consecutive days, the activities of ethoxyresorufin- and methoxyresorufin-Ο-dealkylases were significantly and differentially induced in both liver and lung. Moreover, other CYP isozyme-associated monooxygenase activities were also induced significantly in liver and lung with characteristic induction profiles. Our present results suggest that individual PAHs might have inductive effects on CYP isozymes, and that the characteristic inductive effects of individual PAHs on certain CYP isozymes would be developed as a marker for determining exposure to certain PAHs.

• 생명과학회지
• /
• 제8권6호
• /
• pp.695-701
• /
• 1998

한국산 꽃뱀(Natrix tigrina Lateralis)의 간 마이크로좀에 존재하는 mixed function oxidase system 구성 성분들의 함량과 P45O 의존성 monooxygenase의 활성도를 조사하고 이들을 흰쥐(Sp. D)의 것과 상호 비교하였다. 꽃뱀에서의 P45O, b5 함량 및 NADPH-cytochrome c reductase 활성도는 흰쥐에서 보다 낮았으며, 7-ethoxycoumarin O-deethylase와 benzphetamine N-demethylase 활성도 역시 흰쥐에서 보다 상당히 낮았다. 그러나 aryl hydrocarbon hydroxylase와 testosterone hydroxylase 활성도는 흰쥐와 비교할 때 거의 비슷하거나 오히려 높았다. Testosterone의 수산화 반응에 대한 선택특이성을 조사한 결과, 꽃 뱀은 7$\alpha$ 위치에서, 흰쥐는 6$\beta$ 위치에서 가장 높은 수산화 반응물을 생성했다. 그러나 testosterone의 C2와 C3 위치에서의 수산화 반응에 대한 선택특이성은 꽃뱀과 흰쥐에서 비슷하였다. Radioimmunoassay (RlA)를 실시하여 5종 (CYP2B, CYP1A1, CYP1A2, CYP3A 및 CYP2El)의 P45O 동위효소의 구성비를 비교한 결과, 꽃뱀에서는 CYP1A1/1A2가, 흰쥐에서는 CYP2El이 각각 비교적 많이 존재하였다. 부분정제한 P45O을 SDS-PAGE와 RIA로 분석한 결과, 꽃뱀의 간 마이크로좀에 존재하는 P45O중에는 흰쥐와는 다른 종류의 P45O 동위효소가 존재함을 시사하였다.

• Food Science and Biotechnology
• /
• 제14권2호
• /
• pp.297-300
• /
• 2005

Effects of allyl sulfides on kinetic behavior of cytochrome P450 1 (CYP1)-catalyzed ethoxyresorufin O-deethylase (EROD) activity were studied using microsomes from benzo[a]pyrene-treated human hepatoma cells. Apparent $K_m$ and $V_{max}$ values were calculated as $2.8\;{\mu}M$ and $3.0\;{\mu}mol$ resorufin/min/mg protein based on Lineweaver-Burk plot of microsomal EROD activity, respectively. Diallyl disulfide (DADS) and diallyl trisulfide (DATS) affected $K_m$ and $V_{max}$ values of EROD activity and acted as mixed-type inhibitors for CYP1 isozymes. Apparent Ki values of DADS and DATS were calculated as 1.07 and 0.88 mM, respectively, by re-plotting slopes of Lineweaver-Burk plot and inhibitor concentrations.

• Toxicological Research
• /
• 제11권1호
• /
• pp.31-36
• /
• 1995

Cyclophosphamide (CP) must be enzymatically activated by cytochrome P450(CYP)-linked mixed-function oxidation pathway to be either mutagenic or teratogenic. Influences of alterations in hepatic mixed-function oxidase acitivity and glutathione (GSH) content on the embryotoxicity of CP were studied in rat whole embryo culture system. The embryotoxicity of CP was compared using rat S-9 fraction (S-9) pretreated with chemicals inducing different CYP isozymes, acetone (ACE), Aroclor 1254 (ARO), $\beta$-naphthoflavone (NAF) and phenobarbital (PHE). When 10.5 day embryos were cultured in the immediately centrifuged rat serum for 48 hrs using general gas char{ging schedule, CP$(40{\mu}g/ml)$ with S-9 induced by either NAF or PHE increased the incidence of realformations and significantly decreased embryonic growth compared with the non-induced S-9 group. ACE or ARO induced S-9 group showed no significant difference in embryonic growth. These data suggest that PB and/or NAF inducible CYP isoenzymes are mainly involved in the activation of CP. To examine the effect of GSH on the embryotoxicity of CP, 10.5 day embryos were exposed to CP and S-9 after preincubation with 10 mM of GSH for 3 hrs. In the GSH pretreated group the growth of embryos increased significantly compared with that of the untreated group, suggesting that GSH may protect embryos in culture from some toxic effects of CP.

• 약학회지
• /
• 제54권6호
• /
• pp.522-528
• /
• 2010

This study was designed to examine the effect of estrogen deficiency on the metabolism of ethanol in ovariectomized rats. Female rats were assigned to an ovariectomy (OVX) and a sham (SHAM) surgery group. Gain body weight was greater in incresed in OVX group and especially uterus weight significantly decrease depending on the concentration of estrogen after 3 month of ovariectomy. Ethanol at the tolerative dose (6 g/kg) was injected to rats by oral administration to measure the concentration of ethanol in blood. The area under the blood concentration time curve (AUC) was significantly lower in OVX group than SHAM group. The significant decrease in AUC in OVX group indicates that the estrogen deficiency leads to changes of the factors related to ethanol metabolism. Activity of hepatic alcohol dehydrogenase was not significantly influenced by the ovariectomy and also the ethanol elimination rate in vivo was not different. Cytochrome P450 isozymes did not show any changes except CYP 1A1 and 2E1. Level of hepatic glutathione in OVX group was higher after treatment of ethanol. Therefore the reduction of AUC appears not to be directly associated with the difference of ethanol metabolizing enzyme, but to be related with the physical factors like body weight.