이유된 Sprague Dawley종 숫쥐를 8주간 0.3% butylated hydroxytoluene(BHT)을 넣거나 넣지 않는 soybean oil과 beef tallow를 15% 수준으로 먹이고 9주째 2-acetylaminofluorene(AAF)을 복강으로 주사한 뒤 간 microsome과 cytosol 분획에서 지질 과산화물 함량, superoxide dismutase(SOD), glutathione(GSH) peroxidase, glutathione(GSH) S-trasferase 활성도와 cytochrome P-450의 함량을 측정하였다. AAF가 지질 과산화물 함량과 SOD 활성도에 미치는 영향은 두 식이군에서 유의적인 차이를 보이지 않았다. GSH peroxidase 활성과 cytochrome P-450 함량은 체중 kg당 25mg의 AAF를 투여시 두 식이군에서 모두 증가하였다. 체중 kg당 100mg의 AAF를 투여시 GSH peroxidase 활성도는 soybean oil군에서는 감소하였고 beef tallow군에서는 증가하였다. GSH S-transferase의 활성도는 두 식이군에서 모두 AAF의 투여에 비례하여 증가하였고 식이지방과 BHT는 효소 활성도에 유의적인 영향을 미치지 않았다. 이상의 결과는 불포화지방 식이와 AAF의 투여가 간 microsome의 지질 과산화를 증가시킬 것이나 지질 과산화물에 의해 cytosol의 GSH peroxidase와 GSH S-transferase의 활성도가 증가하여 지질 과산화물을 효과적으로 대사 시켰음을 시사한다.
This study examines the effects of AAF levels and BHT on lipid peroxide metabolizing enzymes in rats fed different dietary fats. Weanling Sprague Dawley male rats were fed beef tallow and soybean oil at 15% with or without 0.3% BHT for 8 weeks. At 9th week, AAF was injected at the level of 25 mg and 100 mg/kg body weight. The lipid peroxide values and cytochrome P-450 contents were determined in liver microsomal fraction, and SOD, GSH peroxidase, GSH S-transferase activities in cytosolic fraction. Effects of AAF on lipid peroxide values and SOD activities were not significantly different. GSH peroxidase activities and cytochrome P-450 contents were elevated at 25 mg AAF in both dietary groups. At 100 mg AAF, GSH peroxidase activities were lowered in soybean oil group, but elevated in beef tallow group. GSH S-transferase activities were elevated by AAF and correlated to the levels of AAF positively in both dietary groups. These results suggest that polyunsaturated fat diet and AAF might increase microsomal lipid peroxidation, but GSH peroxidase and GSH S-transferase activities were elevated by lipid peroxide and metabolized lipid peroxide effectively.
