[The effect of dietary Omega 6 polyunsaturated fatty acids on the activity of enzymes associated with liver mitochondrial and placental function in rats].
Female virgin rats, Wistar strain, divided into three groups of 18 each, were fed either a diet containing 45% of calories as fat (45 g%), the second received low-fat diet (15 g%), before and throughout pregnancy, and the third served as control. For both dietary fat levels, the polyunsaturated to saturated fatty acid (P/S) ratio was adjusted by substitution of saturated fatty acids for corn oil, to provide P/S of 2.0. The control group was fed a diet containing 30% of calories, as fat, with a P/S ratio of 1.0. Rats were sacrificed by decapitation 20 days after mating: fetuses, placenta and liver were then removed and weighed. Liver and placenta mitochondria were isolated. Phospholipids were extracted from mitochondrial membranes, and fatty acid tail composition was determined. Cytochrome c oxidase (a3) and rotenone-insensitive-NADH cytochrome c reductase (NADH cyt c red) in mitochondria subfractions were also assayed. The high-fat diet (45 g%) resulted in an increase in both liver and placental a3, but NADHcyt-c-red, activity did not change. The low fat diet (15 g%) reduced the activity of insensitive rotenone-NADH cytochrome c reductase. The fetal weight of the mothers fed the high-fat diet was higher (p less than 0.001) than in the other groups. No difference in fetal weight was observed between the pregnant groups fed 30% or 15% of calories (fat diets). These results suggest that changes in the fatty acid mitochondrial phospholipids which reflects the composition of dietary fat can result in changes in lipid-dependent function of integral membrane-bound enzymes. Therefore, it can be postulated that the increase of membrane fatty acid Omega 6 enhanced the a3 enzyme activity, which correlated with an increase in fetal growth.
Araya
J
J
Facultad de Medicina, Universidad de Chile, Santiago.
Aguilera
A M
AM
Bosco
C
C
D000818:Animals; D004032:Diet; D003576:Electron Transport Complex IV / Q000378:metabolism; D043371:Fatty Acids, Omega-6; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology*; D005260:Female; D008928:Mitochondria / Q000201:enzymology*; D008930:Mitochondria, Liver / Q000201:enzymology*; D009245:NADH Dehydrogenase / Q000378:metabolism; D010743:Phospholipids / Q000737:chemistry; D010920:Placenta / Q000201:enzymology / Q000648:ultrastructure*; D011247:Pregnancy; D051381:Rats; D011919:Rats, Inbred Strains; D015430:Weight Gain
D043371:Fatty Acids, Omega-6; D005231:Fatty Acids, Unsaturated; D010743:Phospholipids; D009245:NADH Dehydrogenase; D003576:Electron Transport Complex IV
Influencia del contenido de ácidos grasos poliinsaturados Omega 6 dietéticos, en la actividad de enzimas asociadas a la función de la membrana mitocondrial de hígado y placenta de ratas.