Effects of a fish oil-lard diet on rat plasma lipoproteins, liver FAS, and lipolytic enzymes.
The effects of a fish oil concentrate on blood lipids and lipoproteins were examined in relation to their effects on liver fatty acid synthase (FAS), 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase, adipose tissue lipoprotein lipase (LPL), and hepatic triglyceride lipase (H-TGL). For 15 days, 2-mo-old rats were fed a control diet (10% of calories from fat, 4% fat by weight) or diets with 50% of calories (25% wt/wt) provided by lard, lard and fish oil calories (35%/15%), or lard and corn oil (35%/15%). The high-lard diet increased plasma chylomicron and liver triglycerides. The high-lard diet greatly decreased FAS, HMG-CoA reductase, and LPL activities; it also reduced H-TGL activity. Compared with the lard diet, the lard-fish oil diet decreased plasma TG by drastically lowering chylomicron (4-fold, P < 0.001) and very-low-density lipoprotein levels (P < 0.001). It also reduced high-density lipoprotein levels. The lard-fish oil diet prevented hepatic triglyceride accumulation and decreased FAS activity and mass by 3.5-fold (P < 0.001) but did not further decrease HMG-CoA reductase activity. Adipose tissue LPL activity was 2.5-fold (P < 0.001) higher with the lard-fish oil diet than with the lard diet, and H-TGL activity decreased significantly (-32%, P < 0.01), despite unaltered levels of H-TGL mRNA. These effects were significant with only 10% fish oil concentrate in the lard diet. They were not observed with the lard-corn oil diet.(ABSTRACT TRUNCATED AT 250 WORDS)
Benhizia
F
F
Unité de Physiopathologie de la Nutrition, Institut National de la Santé et de la Recherche Médicale U177, Paris, France.
Hainault
I
I
Serougne
C
C
Lagrange
D
D
Hajduch
E
E
Guichard
C
C
Malewiak
M I
MI
Quignard-Boulangé
A
A
Lavau
M
M
Griglio
S
S
D000818:Animals; D004041:Dietary Fats / Q000494:pharmacology*; D004822:Epididymis / Q000201:enzymology; D064429:Fatty Acid Synthases / Q000378:metabolism*; D005395:Fish Oils / Q000494:pharmacology*; D006903:Hydroxymethylglutaryl CoA Reductases / Q000378:metabolism; D008049:Lipase / Q000235:genetics; D008055:Lipids / Q000097:blood; D008066:Lipolysis; D008071:Lipoprotein Lipase / Q000378:metabolism; D008074:Lipoproteins / Q000097:blood*; D008099:Liver / Q000201:enzymology*; D008297:Male; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar
D004041:Dietary Fats; D005395:Fish Oils; D008055:Lipids; D008074:Lipoproteins; D012333:RNA, Messenger; D006903:Hydroxymethylglutaryl CoA Reductases; D064429:Fatty Acid Synthases; D008049:Lipase; D008071:Lipoprotein Lipase; C029310:lard