TY - JOUR
T1 - Effects of Dietary α-Linolenic, Eicosapentaenoic and Docosahexaenoic Acids on Hepatic Lipogenesis and β-Oxidation in Rats
AU - Ikeda, Ikuo
AU - Cha, Jae Young
AU - Yanagita, Teruyoshi
AU - Nakatani, Noriaki
AU - Oogami, Kazuhiro
AU - Imaizumi, Katsumi
AU - Yazawa, Kazunaga
PY - 1998/4
Y1 - 1998/4
N2 - The effects of dietary α-linolenic, eicosapentaenoic and docosahexaenoic acids on the enzyme activities related to hepatic lipogenesis and β-oxidation were compared under constant polyunsaturated/monounsaturated/saturated fatty acids and n-6/n-3 ratios of dietary fats in rats. Dietary fat containing linoleic acid as the sole polyunsaturated fatty acid (PUFA) was also given as a control. The concentration of serum triglyceride and phospholipid in the three n-3 PUFA groups was lower than in the linoleic acid group. The hepatic triglyceride concentration was lower and the phospholipid concentration was higher in the three n-3 PUFA groups than in the linoleic acid group. Cytosolic fatty acid synthase (FAS) activity was lower in the n-3 PUFA groups than in the linoleic acid group, the reduction being more predominant in the eicosapentaenoic acid and docosahexaenoic acid groups than in the α-linolenic acid group. The cytosolic activities of the NADPH-generating enzymes, glucose-6-phosphate dehydrogenase (G6PDH) and the malic enzyme, were lower in the three n-3 PUFA groups. The activity of carnitine palmitoyltransferase (CPT) in mitochondria was higher only in the eicosapentaenoic acid group than in the other groups. The activity of Mg2+-dependent phosphatidate phosphohydrolase (PAP) in microsomes and cytosol was lower in the eicosapentaenoic and docosahexaenoic acid groups than in the linoleic acid group, while there was no effect of dietary fats on the activities of diacylglycerol acyltransferase (DGAT) and glycerol-3-phosphate acyltransferase (G3PAT) in microsomes. The CTP: phosphocholine cytidylyltransferase (CT) activity in the homogenate was lower in the n-3 PUFA groups, the reduction being more prominent in the eicosapentaenoic and docosahexaenoic acid groups than in the α-linolenic acid group. The choline kinase (CK) activity in cytosol was lower in the eicosapentaenoic acid group than in the linoleic acid group. These results showed that dietary α-linolenic, eicosapentaenoic and docosahexaenoic acids differently influenced hepatic lipogenesis and the partition of fatty acid into oxidation or glycerolipid synthesis.
AB - The effects of dietary α-linolenic, eicosapentaenoic and docosahexaenoic acids on the enzyme activities related to hepatic lipogenesis and β-oxidation were compared under constant polyunsaturated/monounsaturated/saturated fatty acids and n-6/n-3 ratios of dietary fats in rats. Dietary fat containing linoleic acid as the sole polyunsaturated fatty acid (PUFA) was also given as a control. The concentration of serum triglyceride and phospholipid in the three n-3 PUFA groups was lower than in the linoleic acid group. The hepatic triglyceride concentration was lower and the phospholipid concentration was higher in the three n-3 PUFA groups than in the linoleic acid group. Cytosolic fatty acid synthase (FAS) activity was lower in the n-3 PUFA groups than in the linoleic acid group, the reduction being more predominant in the eicosapentaenoic acid and docosahexaenoic acid groups than in the α-linolenic acid group. The cytosolic activities of the NADPH-generating enzymes, glucose-6-phosphate dehydrogenase (G6PDH) and the malic enzyme, were lower in the three n-3 PUFA groups. The activity of carnitine palmitoyltransferase (CPT) in mitochondria was higher only in the eicosapentaenoic acid group than in the other groups. The activity of Mg2+-dependent phosphatidate phosphohydrolase (PAP) in microsomes and cytosol was lower in the eicosapentaenoic and docosahexaenoic acid groups than in the linoleic acid group, while there was no effect of dietary fats on the activities of diacylglycerol acyltransferase (DGAT) and glycerol-3-phosphate acyltransferase (G3PAT) in microsomes. The CTP: phosphocholine cytidylyltransferase (CT) activity in the homogenate was lower in the n-3 PUFA groups, the reduction being more prominent in the eicosapentaenoic and docosahexaenoic acid groups than in the α-linolenic acid group. The choline kinase (CK) activity in cytosol was lower in the eicosapentaenoic acid group than in the linoleic acid group. These results showed that dietary α-linolenic, eicosapentaenoic and docosahexaenoic acids differently influenced hepatic lipogenesis and the partition of fatty acid into oxidation or glycerolipid synthesis.
KW - α-linolenic acid
KW - β-oxidation
KW - Docosahexaenoic acid
KW - Eicosapentaenoic acid
KW - Lipogenesis
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M3 - Article
C2 - 9614698
AN - SCOPUS:0032038062
VL - 62
SP - 675
EP - 680
JO - Bioscience, Biotechnology and Biochemistry
JF - Bioscience, Biotechnology and Biochemistry
SN - 0916-8451
IS - 4
ER -