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The effects of dietary protein on the fatty acid composition and Δ6 desaturase activity of rat hepatic microsomes
Author(s) -
Lindholm Marie,
Eklúnd Anders
Publication year - 1991
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/bf02544003
Subject(s) - linoleic acid , arachidonic acid , oleic acid , microsome , phospholipid , phosphatidylcholine , fatty acid , phosphatidylethanolamine , casein , biochemistry , microsoma , biology , chemistry , phosphatidylinositol , lipidology , medicine , endocrinology , enzyme , kinase , membrane
Recently, significant differences between rats fed a casein diet and rats fed a soybean protein diet have been observed in hepatic phospholipid fatty acid patterns (Sjöblom, L., and Eklund, A., Biochim. Biophys. Acta 1004 , 187–192, 1990). The influence of these two diets on the Δ6 desaturase activity was investigated in the present study because the hepatic desaturase system is a source of unsaturated fatty acids. The rats fed a casein diet showed higher desaturase activity than those fed soybean protein when using either linoleic acid (P<0.005) or oleic acid (P<0.05) as substrates. The phosphatidylcholine fraction of hepatic microsomes showed increases in oleic acid (P<0.005) and 20∶3ω9 (P<0.001) levels as well as decreases in stearic acid (P<0.001), linoleic acid (P<0.005) and arachidonic acid (P<0.005) levels in rats which were fed casein rather than soybean protein. Similar differences between the two groups were also observed in the phosphatidylethanolamine and phosphatidylinositol fractions. These data indicate that the qualitative properties of the dietary protein source may influence the fatty acid pattern of rat hepatic microsomes by interfering with Δ6 desaturase activity.