Induction of Hepatic Cytochrome P450 Using Dietary Oxidized Oil in Iron Deficient Rats

炸油攝食對缺鐵大鼠肝微粒體細胞色素P450誘發之影響

張美鈴(Mei-Ling Chang) ； 黃惠玲(Hui-Ling Huang) ； 蕭寧馨(Ning-Sing Shaw)

《中華民國營養學會雜誌》 25卷4期 (2000/12) Pp. 207-218

https://doi.org/10.6691/JCNS.200012_25(4).0003

摘要

本研究探討炸油攝食對輕微與嚴重缺鐵大鼠肝臟微粒體細胞色素P450誘發之影響。實驗用炸油為新鮮黃豆油經205 ± 5℃油炸麵粉片共24小時而得。離乳雄性Wistar大鼠隨機分配為體重相當之三組，分別餵食鐵正常（45 ppm Fe），低鐵（20 ppm Fe）與缺鐵飼料（6 ppm Fe）；飼料依據AIN-76配方，其中含黃豆油15%，並依實驗需要以硫酸亞鐵調整其鐵濃度。經10天飼養後缺鐵大鼠血紅素降為1.55mmol/L而呈貧血症狀，各組再隨機分為新鮮油與炸油兩組，炸油組飼料以等量炸油取代黃豆油，而鐵量維持不變，繼續飼養32天後，犧牲動物取其血液與肝臟進行生化與化學分析。結果可見：炸油組之肝微粒體細胞色素P450濃度顯著高於新鮮油組（p = 0.0001），炸油各組之肝微粒體細胞色素P450總量對體重之比例並不因缺鐵程度而有差異（p = 0.38）；鐵營養狀況相同時，炸油明顯抑制體重與飼料效率，尤以對缺鐵組的影響最大；炸油使低鐵組的血紅素濃度明顯降低，也使鐵正常與低鐵組之肝鐵蛋白總量降低，但是不影響其肝鐵總量；炸油各組肝臟之TBARS值顯著較新鮮油各組為高，其中又以鐵正常組明顯高於低鐵組。根據以上結果而知：長期炸油攝食時，肝微粒體細胞色素P450之誘發不因輕微或嚴重缺鐵而受限，但是膳食炸油加上缺鐵會嚴重阻礙成長與飼料之利用效率，並且有降低血紅素之虞慮，而且肝鐵的儲存與代謝有因炸油而改變的現象。

關鍵字

肝臟細胞色素P450 ； 炸油 ； 缺鐵 ； 肝鐵蛋白 ； 大鼠

並列摘要

This study was conducted to investigate the effects of mild and severe iron deficiency on the induction of hepatic cytochrome P450 (CYP) using oxidized oil. Oxidized oil was prepared from soybean oil subjected to deep-frying, heated at 205 ± 5℃ for 24 hours. All experimental diets were based on the AIN-76 formula but contained 15% fresh or oxidized soybean oil. Weanling, male Wistar rats were randomly assigned to three iron diets containing fresh oil: control (45 ppm Fe), low Fe (20 ppm) and Fe deficient (6 ppm) groups. After 10 days on the diet, each iron group was further divided into fresh oil and oxidized oil groups, and feeding continued for 32 days. Microsomal CYP concentration was significantly higher in the oxidized oil groups. Among the oxidized oil groups, total hepatic CYP content was not significantly different when normalized on a body weight basis. For all iron groups, consumption of oxidized oil suppressed growth, body weight gain and feed efficiency. This suppression was most severe in the iron deficient group. Hemoglobin concentration in rats fed a low iron diet was also suppressed by feeding oxidized oil. In the control and low Fe group, oxidized oil led to a significant reduction in total amount of hepatic ferritin, but total hepatic iron remained unchanged. Hepatic TBARS value was elevated significantly in the oxidized oil groups, among which the control group had significantly higher TBARS values than the other two groups. These results indicated the CYP induction was not compromised by severe iron deficiency, but was maintained at the expense of other heme proteins and body growth. Consumption of oxidized oil appears to alter iron metabolism and reduce the storage form of iron in the liver.

並列關鍵字

hepatic cytochrome P450 ； oxidized oil ； iron deficiency ； hepatic ferritin ； rats