M. Sakono et al., COMBINED EFFECTS OF DIETARY-PROTEIN AND FAT ON LIPID-METABOLISM IN RATS, Journal of nutritional science and vitaminology, 39(4), 1993, pp. 335-343
The combined effects of dietary protein (casein, whey protein, or soy
protein) and fat (safflower oil, perilla seed oil, or their mixed oil;
linoleic acid/a-linolenic acid=5.0) on several lipid parameters were
studied in rats. Serum cholesterol and triglyceride levels were lower
in perilla seed oil groups irrespective of the protein sources. Liver
triglyceride level, and fecal excretion of steroids were influenced ma
inly by protein sources, particularly isolated soy protein lowered liv
er triglyceride level, and increased the fecal steroid excretion. The
fatty acid composition of liver phosphatidylcholine was influenced by
dietary fat sources., The proportion of arachidonic acid was significa
ntly lower in rats fed perilla seed oil than in those fed safflower oi
l or mixed oil, while the proportion of eicosapentaenoic acid was high
er in rats fed perilla seed oil than in those fed safflower oil. Arach
idonic acid/linoleic acid ratio was significantly lower in perilla see
d oil groups, and tended to be higher in casein groups. Eicosapentaeno
ic acid/arachidonic acid ratio was influenced by both dietary protein
and fat, and protein-fat interaction was observed. Eicosapentaenoic ac
id/arachidonic acid ratio was higher in perilla seed oil groups, and i
solated soy protein in perilla seed oil groups lowered the ratio in co
mparison with other protein sources in perilla seed oil groups.