Feeding of a deep-fried fat causes PPARalpha activation in the liver of pigs as a non-proliferating species.
Recent studies have shown that dietary oxidised fats influence the lipid metabolism in rats by activation of PPARalpha. In this study, we investigated whether a mildly oxidised fat causes activation of PPARalpha in pigs which are non-proliferators like man. Eighteen pigs were assigned to two groups and received either a diet containing 90 g/kg of a fresh fat or the same diet with 90 g/kg of an oxidised fat prepared by heating for 24 h at 180 degrees C in a deep fryer. Pigs fed the oxidised fat had a higher peroxisome count, a higher activity of catalase and a higher mRNA concentration of mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase in the liver and a higher concentration of 3-hydroxybutyrate in plasma than pigs fed the fresh fat (P< 0.05). Hepatic mRNA concentrations of acyl-CoA oxidase and carnitine palmitoyltransferase- 1 tended to be increased in pigs fed the oxidised fat compared to pigs fed the fresh fat (P< 0.10). Pigs fed the oxidised fat, moreover, had higher mRNA concentrations of sterol regulatory element-binding protein (SREBP)-1 and its target genes acetyl-CoA carboxylase and stearoyl-CoA desaturase in the liver and higher mRNA concentrations of SREBP-2 and its target genes 3-hydroxy-3-methylglutary-CoA reductase and LDL receptor in liver and small intestine. In conclusion, this study shows that even a mildly oxidised fat causes activation of PPARalpha in the liver of pigs. Up-regulation of SREBP and its target genes in liver and small intestine suggests that the oxidised fat could stimulate synthesis of cholesterol and TAG in these tissues.
Luci
Sebastian
S
Institute of Agricultural and Nutritional Sciences, Martin-Luther- University of Halle- Wittenberg, Emil-Abderhalden-Strasse 26, D-06108 Halle (Saale), Germany.
König
Bettina
B
Giemsa
Beatrice
B
Huber
Stefanie
S
Hause
Gerd
G
Kluge
Holger
H
Stangl
Gabriele I
GI
Eder
Klaus
K
D020155:3-Hydroxybutyric Acid / Q000097:blood; D000818:Animals; D000975:Antioxidants / Q000032:analysis; D001835:Body Weight / Q000502:physiology; D002784:Cholesterol / Q000032:analysis / Q000097:blood; D003296:Cooking; D004041:Dietary Fats / Q000008:administration & dosage* / Q000378:metabolism; D020895:Enterocytes / Q000378:metabolism; D005227:Fatty Acids / Q000032:analysis; D015870:Gene Expression / Q000235:genetics; D050356:Lipid Metabolism / Q000235:genetics; D015227:Lipid Peroxidation / Q000235:genetics; D008074:Lipoproteins / Q000378:metabolism; D008099:Liver / Q000378:metabolism*; D008297:Male; D008862:Microsomes, Liver / Q000378:metabolism; D008930:Mitochondria, Liver / Q000235:genetics / Q000378:metabolism; D047493:PPAR alpha / Q000378:metabolism*; D020675:Peroxisomes / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D051779:Sterol Regulatory Element Binding Proteins / Q000235:genetics; D013552:Swine; D014280:Triglycerides / Q000032:analysis / Q000097:blood
D000975:Antioxidants; D004041:Dietary Fats; D005227:Fatty Acids; D008074:Lipoproteins; D047493:PPAR alpha; D012333:RNA, Messenger; D051779:Sterol Regulatory Element Binding Proteins; D014280:Triglycerides; D002784:Cholesterol; D020155:3-Hydroxybutyric Acid