Effect of dietary protein on the peroxidation of eicosapentaenoic acid in stroke-prone spontaneously hypertensive rats.
In order to investigate the effect of dietary EPA on liver GSH peroxidase (GSH-Px) activity in rats, highly concentrated EPA (78% ethyl ester form) was administrated to SHRSP (Stroke-prone spontaneously hypertensive rat) that were fed a casein, SPI (soybean protein isolate) or SPI diet with methionine for 4 weeks. The content of liver GSH in rats fed SPI was lower than that of rats fed the casein diet. Although no significant difference of liver GSH-Px was observed in rats after EPA supplement, a decrease of liver GSH-Px activity was found in rats fed the SPI diet when compared with rats fed the casein diet. The changes of liver GSH content and GSH-Px activity in rats fed SPI were found to be associated with methionine supplement. Addition of methionine to the SPI diet resulted in an increase of liver GSH content and GSH-Px activity. In addition, liver lipid peroxide concentration was increased in rats fed the SPI diet after EPA treatment. In contrast, EPA administered rats fed the SPI diet containing methionine showed a lower liver lipid peroxide concentration. These results suggest that methionine may play an important role in regulation of the utilization of EPA in SHRSP when fed a SPI diet.
Chiang
M T
MT
Department of Food Science, Faculty of Agriculture, Tohoku University, Sendai, Japan.
Kimura
S
S
D000818:Animals; D002561:Cerebrovascular Disorders / Q000235:genetics / Q000378:metabolism / Q000517:prevention & control*; D004044:Dietary Proteins / Q000494:pharmacology*; D015118:Eicosapentaenoic Acid / Q000378:metabolism*; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D006973:Hypertension / Q000150:complications / Q000178:diet therapy* / Q000378:metabolism; D015227:Lipid Peroxidation / Q000502:physiology*; D008297:Male; D008715:Methionine / Q000494:pharmacology*; D014674:Plant Proteins, Dietary / Q000494:pharmacology; D051381:Rats; D011918:Rats, Inbred SHR; D030262:Soybean Proteins; D013025:Glycine max
D004044:Dietary Proteins; D014674:Plant Proteins, Dietary; D030262:Soybean Proteins; D015118:Eicosapentaenoic Acid; D008715:Methionine; D005979:Glutathione Peroxidase; D005978:Glutathione