Plasma Lipids, Including Individual Phospholipids, in Pregnant Rats

Vikrot, Olle

doi:10.1111/j.0954-6820.1965.tb04326.x

Cited by 9 publications

References 15 publications

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The fatty acid composition of the main phospholipid fractions of the rumen and abomasum tissues of foetal and adult sheep

Body¹,

Shorland²

1974

J Sci Food Agric

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The fatty acid composition has been determined on phosphatidyl choline, phosphatidyl ethanolamine and sphingomyelin fractions earlier isolated from the rumen and abomasum tissues of foetal and of adult Romney sheep.The major proportion of polyunsaturated fatty acids was found in the phosphatidyl ethanolamine (17 to 43 %) fraction and this was reduced in the phosphatidyl choline (7 to 25 %) and sphingomyelin (1 to 4 %) fractions. These features are in keeping with the results for mammalian tissues generally. The phosphatidyl ethanolamine fractions were further characterised by the low content of palmitic acid (4 %) compared with 25 to 30% in the phosphatidyl choline fractions and 29 to 52 % in the sphingomyelin fractions and by the occurrence of cyclopropane fatty acids. Consistent with the findings of other workers on mammalian tissues, the sphingomyelin fractions contained a relatively high content (16 to 27%) of higher maturated fatty acids including 22: 0,23 : 0,24: 0 and 25 : 0 and of tetracos-14-enoic (24: 1 w9) acid (5 to 16%). The total amounts of acids above Czo tended to vary inversely with the levels of palmitic acid whereas the levels of stearic acid were relatively constant at 13 to 17%. Changes in fatty acid composition with age were generally not marked but the tissues of the foetus were distinguished from those of the adult by their substantial amount of eicosa-5,8,1l-trienoic (20: 3 09) acid together with relatively low contents of linoleic (18: 2 w6) and linolenic (1 8: 3 w3) acids and to a lesser extent by reduced level of acids of the w3 series. This was particularly reflected by the ratios of w6/w3 Czo + Cz2 acids in the phosphatidyl ethanolamine fractions, the values for the foetal rumen and abomasum tissues being 1.03 and 1.07, respectively, compared with corresponding values of 0.78 and 0.72 found in adult sheep.The results are consistent with a requirement for Czo and C,, polyunsaturated acids of the w3 and w6 series and some penetration of maternal fatty acids through the placenta. The resemblance between the fatty acid make-up and composition of foetal and maternal phospholipids suggests the possibility of transference of intact or lyso-phospholipids from the mother to the foetus through the placenta. However, such a possibility is counter-indicated by consideration of previous work using labelled intermediates and by the mechanism of conversion of linoleic and linolenic acids requiring their CoA derivatives in the formation of the corresponding polyunsaturated Cz0 4 Czz acids. Nevertheless, the sharp cut-off of exogenous maternal fatty acids from the foetal triglycerides and their inclusion in the foetal phospholipids are not readily explainable.

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The fatty acid composition of the main phospholipid fractions of the rumen and abomasum tissues of foetal and adult sheep

Body¹,

Shorland²

1974

J Sci Food Agric

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The phospholipid composition of plasma in various mammalian species

Nelson

1967

Lipids

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Plasma phospholipids in several common mammalian species, including cat, cow, dog, goat, guinea pig, horse, pig, rabbit, rat, and sheep, were analyzed by using chromatographic and spectrophotometric methods. Lipids were extracted from plasma with chloroform-methanol 2ratio1 (v/v) and freed of nonlipid material by passage through a Sephadex column. The phospholipids were separated by two-dimensional thin-layer chromatography (TLC). Spots were identified by spray reagents, also by infrared spectrophotometry. The relative distribution of the phospholipids was determined by phosphorus analysis on the spot scraped off the TLC plate.Lecithin, lysolecithin, and sphingomyelin were found in the plasma of all species and accounted for more than 95% of the phospholipids except in the rodents. Lecithin was without exception the major phospholipid in plasma (56 to 83%). Lysolecithin and sphingomyelin content varied between 8 and 23% and 6 and 15% respectively. Phosphatidyl ethanolamine and phosphatidyl inositol were the only noncholine-containing phospholipids detected (detection limits 0.2%) in the plasma of these species. Together these compounds usually made up less than 5% of the total phospholipid. Rodents were an exception, especially the guinea pig, which had 21.7% phosphatidyl ethanolamine.

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