MORIO Michio Chugoku Rousai Hospital Dean, 院長 (80033950)
SATO Nobuyoshi Cleave land Clinic Researcher, クリニック, 研究員 (30225982)
長尾 正和 広島大学, 医学部, 助手 (90164128)
FUJII Kohyu Hiroshima Univ. school of Med. Assist. Prof., 医学部, 講師 (60034021)
YUGE Osafumi Hiroshima Univ. school of Med. Prof., 医学部, 教授 (40034128)
|Budget Amount *help
¥3,500,000 (Direct Cost : ¥3,500,000)
Fiscal Year 1992 : ¥700,000 (Direct Cost : ¥700,000)
Fiscal Year 1991 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1990 : ¥2,200,000 (Direct Cost : ¥2,200,000)
1. Pentane was measured in a mixture of guinea pig liver microsomes and carbontetrachloride in the presence of NADPH and under anaerobic conditions by gas chromatography. Pentane of 0.2 pmol/mg protein/min was formed in the presence of NADPH without CCl4. Pentane formation increased to 2.0 pmol/mg protein/min in the presence of CCl4 and NADPH. This reaction required an anaerobic stomosphere, 2.1 mmol/liter of NADPH and 13.4 mmol/liter of CCl4 under optimal conditions. The formation was reduced in the presence of oxygen, glutathione, vitamin E, and metyrapone. These results clearly show that pentane is formed by lipid peroxidation initiated by the free radical cleavage products of CCl4, which are anaerobically produced by NADPH-dependent microsomal enzymes. We conclude that is good index of in vitro lipid peroxidation via microsomal NADPH-P450 enzyme system.
2. The formation of pentane and anaerobic metabolites of halothane in a mixture of guinea pig liver microsomes and halothane in the
presence of NADPH was studied by gas chromatography. Under anaerobic conditions, pentane was formed without halothane and was inhibited by oxygen tension. This anaerobic pentane formation was potentiated 2.5 times by addition of halothane. Halothane-induced pentane formation increased dose-dependently with a halothane concentration of up to 2.1 mmol/liter and then decreased in the presence of increasing concentration of halothane. Inhibition by a higher substrate was also observed in the formation of anaerobic metabolites of halothane. Antioxidants, Vitamin E and glutathione, reduced the pentane formation, but did not reduce the formation of the anaerobic metabolites of halothane. Metyrapone, an inhibitor of cytochrome P-450, reduced with the pentane and anaerobic metabolites of halothane. These results show halothane-induced lipid peroxidation in association with the anaerobic metabolism of halothane in guinea pig liver microsomes.
3. The formation of pentane in a mixture of guinea pig liver microsomes and sevoflurane in the presence of NADPH was studied by gas chromatography. Pentane was formed without sevoflurane. This pentane formation was potentiated by addition of sevoflurane. Sevoflurane-induced pentane formation increased dose-dependently with a sevoflurane concentration. Antioxidants, Vitamin E and glutathione, reduced the pentane formation. These results suggest that sevoflurane induced lipid peroxidation in guinea pig liver microsomes.