Effect of dietary lipid on gamma-glutamyl transferase-positive foci during hepatocarcinogenesis in rats.
The effect of dietary lipid on gamma-glutamyl transferase-positive (GGT-positive) foci was investigated. Female Sprague-Dawley rats were dosed with diethylnitrosamine (15 mg/kg) at 24 h of age. After weaning, they were fed nutritionally complete semipurified diets for 3 months. Rats fed 15% corn oil had significantly lower hepatic phospholipid eicosapentaenoate and docosahexaenoate than rats fed 7.5% corn oil plus 7.5% fish oil, 5% corn oil plus 10% fish oil (P < 0.05). However, rats fed 15% corn oil had significantly greater hepatic phospholipid arachidonate than rats fed the other two diets (P < 0.05), suggesting that n-3 polyunsaturated fatty acids were incorporated into hepatic phospholipid at the expense of n-6 polyunsaturated fatty acids. Hepatic PGF2alpha content was significantly greater in rats fed 15% corn oil than in rats fed the other two diets (P < 0.05). Rats fed fish oil had significantly lower hepatic vitamin E content than rats fed corn oil (P < 0.05). Hepatic lipid peroxidation (TBARS) tended to increase with increased dietary fish oil (P < 0.05). Dietary lipid did not influence GGT-positive foci area or number. In conclusion, dietary lipid affected hepatic PGF2alpha production, however, showed no effect on GGT-positive foci area and number. This may suggest that PGF2alpha is not the underlying mechanism for GGT-positive foci during hepatocarcinogenesis.
Lii
C K
CK
Department of Nutrition, Chung Shan Medical College, Taichung, Taiwan.
Ko
J J
JJ
Chen
H W
HW
D000818:Animals; D016718:Arachidonic Acid / Q000032:analysis; D003314:Corn Oil / Q000494:pharmacology; D004042:Dietary Fats, Unsaturated / Q000494:pharmacology*; D004052:Diethylnitrosamine / Q000008:administration & dosage; D015237:Dinoprost / Q000032:analysis*; D004281:Docosahexaenoic Acids / Q000032:analysis; D015118:Eicosapentaenoic Acid / Q000032:analysis; D005260:Female; D005395:Fish Oils / Q000494:pharmacology; D005982:Glutathione Transferase / Q000032:analysis; D015227:Lipid Peroxidation / Q000187:drug effects; D008099:Liver / Q000737:chemistry* / Q000201:enzymology; D008114:Liver Neoplasms, Experimental / Q000737:chemistry / Q000201:enzymology / Q000209:etiology*; D019301:Oleic Acid / Q000032:analysis; D010168:Palmitates / Q000032:analysis; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013228:Stearates / Q000032:analysis; D014810:Vitamin E / Q000032:analysis; D005723:gamma-Glutamyltransferase / Q000378:metabolism*
D004042:Dietary Fats, Unsaturated; D005395:Fish Oils; D010168:Palmitates; D013228:Stearates; D014810:Vitamin E; D004281:Docosahexaenoic Acids; D016718:Arachidonic Acid; D019301:Oleic Acid; D004052:Diethylnitrosamine; D003314:Corn Oil; D015118:Eicosapentaenoic Acid; D015237:Dinoprost; D005723:gamma-Glutamyltransferase; D005982:Glutathione Transferase