Disparate effects of dietary fatty acids on activity of 5'-nucleotidase of rat liver plasma membrane.
The effects of incorporation of dietary n-3 polyunsaturated fatty acids (PUFA) into rat liver plasma membrane on the activity of 5'-nucleotidase (EC 3.1.3.5) was studied. The membrane phospholipids from rats fed a diet containing 10% by weight menhaden oil (MO) for 3 wk contained more n-3 PUFA and less n-6 PUFA in phospholipids classes, i.e., 24% and 65% less linoleic and arachidonic acid in phosphatidylcholine, than in rats fed 10% coconut oil (CNO) diets. The specific activity of 5'-nucleotidase in n-3 PUFA-enriched hepatic plasma membranes was 1.6- to 2-fold higher than that in rats fed CNO or corn oil (CO). Lineweaver-Burk plots for 5'-nucleotidase in liver plasma membranes isolated from rats fed MO and CNO showed no significant differences in Km values but the Vmax was increased by 67% in MO-fed rats. Arrhenius plots showed a break point in 5'-nucleotidase activity at 28.3 degrees C and 30.8 degrees C in plasma membranes from MO- and CNO-fed rats, respectively. The implications of this in the generation of adenosine and its possible impact on physiological functions are discussed.
Zuniga
M E
ME
Institute of Food Science, Cornell University, Ithaca, NY 14853.
Lokesh
B R
BR
Kinsella
J E
JE
D015720:5'-Nucleotidase; D000818:Animals; D002462:Cell Membrane / Q000201:enzymology / Q000378:metabolism; D002784:Cholesterol / Q000378:metabolism; D004042:Dietary Fats, Unsaturated / Q000494:pharmacology*; D004789:Enzyme Activation; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology*; D005395:Fish Oils / Q000494:pharmacology; D008099:Liver / Q000201:enzymology* / Q000378:metabolism; D008297:Male; D008560:Membrane Fluidity; D008563:Membrane Lipids / Q000378:metabolism; D009708:Nucleotidases / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D004042:Dietary Fats, Unsaturated; D005231:Fatty Acids, Unsaturated; D005395:Fish Oils; D008563:Membrane Lipids; D010743:Phospholipids; C033266:Menhaden oil; D002784:Cholesterol; D009708:Nucleotidases; D015720:5'-Nucleotidase