Effects of Various Dietary Fats on Cardiolipin Acyl Composition During Ontogeny of Mice

January 1, 1992 Human Health and Nutrition Data 0 Comments

Effects of Various Dietary Fats on Cardiolipin Acyl Composition During Ontogeny of Mice

Year: 1992
Authors: Berger, A. Gershwin, M.E. German, J.B.
Publication Name: Lipids
Publication Details: Volume 27; Pages 605 – 612.

Abstract:

Cardiolipin (CL) is a unique mitochondrial phospholipid, containing up to 85 wt% 18:2n-6 in mammals. The influence of maternal dietary fatty acids on the acyl composition of offspring CL has not been examined previously. Adult female mice were thus fed diets rich in 18:1n-9 (olive oil), 18:2n-6 (safflower oil), 18:3n-3 (linseed oil) or 20:5n-3 and 22:6n-3 (fish oil/safflower, 9.1, w/w), for a five month period, encompassing two breeding cycles. Offspring from the second breeding cycle were then fed these diets. The acyl composition of CL, phosphatidylcholine and phosphatidylethanolamine from liver and heart was evaluated from mice killed 3, 18 and 42 days after parturition. The primary nutrient sources at these three time points were transplacental nutrients, breast milk and the diet, respectively. Maternal diet was found to influence the acyl composition of CL via both placental transfer of fatty acids and breast milk. Fish oil feeding resulted in replacement of a substantial portion of 18:2n-6 with 22:6n-3; after 42 days, the area% of 18:2n-6 in heart CL was reduced from 62% in safflower oil fed mice to 12%. In comparison to fish oil feeding, linseed oil feeding resulted in a much lower accumulation of 22:6n-3. Olive oil feeding resulted in substantial replacement of 18:2n-4 with 18:1n-9 {18:2n-6 was reduced from 62% to 31%}. Physiologically, these findings are relevant because changes in CL acyl composition may influence the activity of associated inner mitochondrial membrane enzymes. (Author�s abstract)
Cardiolipin (CL) [l'-(1,2-diacyl-sn-glycero-3-phosphoryl}-3'-(l”,2″-diacyl-sn-glycero-3″-phosphoryl)-sn-glycerol; or 1,3-bis(3-sn-phosphatidyl)glycerol] is a unique mitochondrial phospholipid. In mammals, CL may contain up to 85 wt% 18:2n-6. Alterations of the fatty acyl moiety of CL can influence the binding to antiphospholipid antibodies (aPL) in vitro.The influences of long-term maternal fat consumption on the CL acyl composition of offspring tissues during ontogeny has not been studied previously. The extent to which dietary fatty acids of the n-9 and n-3 series could displace the predominating n-6 fatty acid, 18:2n-6 from CL was the focus. Independent of diet, all the experimental groups were born with a higher content of 18:1 in CL that was gradually replaced with other fatty acids derived from breast milk and the diet.
The very high levels of 22:6n-3 incorporated into cardiac CL in the present study reflects the long-term feeding of a diet rich in n-3 polyenoic acids, but is not dependent on the fact the diet was fed through two generations, since similarly high levels of 22:6n-3 were observed in the CL of adult mice fed fish off for five months. The data indicate that fish oils can decrease the content of 18:2n-6 in CL to a greater extent than LA or ALA or hydrogenated corn oil diets. An
apparent selective uptake of 22:6n-3 into heart CL was evident during the transfer of both maternal transplacental and breast milk derived 22:6n-3. The results suggest that 22:6n-3 derived from breast milk, or released from other organs such as adipose tissue and liver, was selectively retained by heart cells. These results emphasize the importance of evaluating the phospholipid acyl moiety of more than one tissue in dietary lipid studies. In cardiac PE, the fact that levels of 22:5n-3 were considerably higher after linseed oil feeding as compared to fish oil feeding suggests that the conversion of 22:5n-3 to 24:5n-3 may be limiting. The data indicate that 18:2n-6 accumulates in CL because it is very abundant in most animal diets, and that other fatty acids, such as 18:1n-9 and 22:6n-3, may replace 18:2n-6 when provided in sufficient amounts in the diet. The following fatty acids are more abundant in CL relative to other phospholipids or can be enriched in CL by dietary means: 16:1n-7, 18:1n-7, 18:1n-9, 18:2n-6, 5t,9c,12c-octadecatrienoate, 20:2n-6, 20:3n-3, 22:1n-9 and 22:6n-3. There is evidence from dietary studies that modulation of the acyl chain of CL can influence the activity of associated inner mitochondrial membrane proteins. In summary, this study demonstrated that 18:1n-9 present in olive oil and 22:6n-3 present in fish oil can replace a significant portion of 18:2n-6 in hepatic and cardiac CL of newborn mice These fatty acids will continue to accumulate during nursing and active feeding of the offspring, provided they are fed in sufficient quantities and for a long enough duration. The major difference between linseed oil (rich in 18:3n-3) and fish off feeding (rich in 22:6n-3) was that 22:6n-3 accumulated extensively in heart CL only when fed as intact 22:6n-3. Levels of 20:5n-3 and 22:5n-3 were equivalent or greater with linseed oil feeding in CL, PC and PE. These findings may be relevant to human populations who consume diets rich in 18:1n-9 (Mediterraneans), 18:2n-6 (Americans) and 20:5n-3/22:6n-3 (Eskimos and individuals ingesting fish and fish oils). Physiologically, these findings may be important because alterations in CL acyl moiety may influence the activity of associated inner mitochondrial membrane enzymes. The ramifications of altering the acyl composition of CL during development have not been investigated. (Editor�s comments)



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