scholarly journals The oxidation and utilization of palmitate, stearate, oleate and acetate by the mammary gland of the fed goat in relation to their overall metabolism, and the role of plasma phospholipids and neutral lipids in milk-fat synthesis

1967 ◽  
Vol 102 (3) ◽  
pp. 637-647 ◽  
Author(s):  
E. F. Annison ◽  
J. L. Linzell ◽  
S Fazakerley ◽  
B. W. Nichols

1. Measurements were made of milk yield, mammary blood flow and arteriovenous differences of each plasma lipid fraction, and their specific radioactivities, during the infusion of [U-(14)C]stearate, [U-(14)C]oleate, [U-(14)C]palmitate and [1-(14)C]acetate into fed lactating goats. 2. Entry rates of fatty acids into the circulation were 4.2mg./min./kg. body wt. for acetate, and 0.18, 0.28 and 0.42mg./min./kg. for stearate, oleate and palmitate respectively. Acetate accounted for 23% of the total carbon dioxide produced by the whole animal, and contributed to the oxidative metabolism of the mammary gland to about the same extent. Corresponding values for each of the long-chain acids were less than 1%. 3. There were no significant arteriovenous differences of phospholipids, sterols or sterol esters, and their fatty acid composition showed no net changes during passage through the mammary gland. 4. There were large arteriovenous differences of plasma triglycerides, and their fatty acid composition showed marked changes across the gland. The proportions of palmitate and stearate fell, and that of oleate increased. 5. Arteriovenous differences of plasma free fatty acids (FFA) were small and variable, but a large fall in the specific radioactivity of each of the long-chain acids examined indicated substantial uptake of plasma FFA, accompanied by roughly equivalent FFA release from mammary tissue. The uptake of FFA was confirmed by the extensive transfer of radioactivity into milk. The FFA of milk were similar in composition and radioactivity to the milk triglyceride fatty acids, and quite unlike plasma FFA. 6. The formation of large amounts of oleic acid (18-21 mg./min.) from stearic acid was demonstrated. 7. During the terminal stages of the [(14)C]acetate infusion, milk triglyceride fatty acids of chain length C(4)-C(14) showed specific radioactivities that were 75-90% of that of blood acetate, and that of palmitate was roughly one-quarter of this value. Oleate and stearate were unlabelled. 8. The results confirmed that milk fatty acids of chain length C(4)-C(14) arise largely from blood acetate, and palmitate is derived partly from acetate and partly from plasma triglyceride, the latter fraction being almost the sole precursor of oleate and stearate.

1999 ◽  
Vol 1999 ◽  
pp. 115-115 ◽  
Author(s):  
A.M. Wachira ◽  
L.A. Sinclair ◽  
R.G. Wilkinson ◽  
G. Demirel ◽  
M. Enser ◽  
...  

The benefits of long chain polyunsaturated fatty acids (PUFA) to human health, especially those of the n-3 series are now widely recognised. In a previous experiment (Wachira et al. 1998) supplementing diets with whole linseed or fish oil increased n-3 fatty acid levels in lamb muscle. To raise these further the whole linseed can be treated with formaldehyde to increase protection in the rumen. Dietary antioxidants such as vitamin E can control lipid oxidation but information on their effects on lamb performance and fatty acid composition is limited. The current experiments investigated the effects of different dietary PUFA sources and vitamin E levels on growth and fatty acid composition in two sheep breeds. Detailed results of the effects of vitamin E are presented in the accompanying abstract by Enser et al.


2000 ◽  
Vol 84 (1) ◽  
pp. 103-109 ◽  
Author(s):  
Franca Marangoni ◽  
Carlo Agostoni ◽  
Anna M. Lammard ◽  
Marcello Giovannini ◽  
Claudio Galli ◽  
...  

While a wealth of data on the fatty acid composition of mature human milk has been published, limited information is available on the quantities of individual fatty acids supplied to the suckling infant with maternal milk, through the whole first year of life. Our aim was to qualitatively and quantitatively evaluate the fatty acid composition of human milk from Italian mothers, throughout extended lactation with particular emphasis on the long-chain polyunsaturated fatty acids. We have thus measured the total fat content and the concentrations of major fatty acids by quantitative GLC in pooled breast hindmilk collected from all feedings over 24 h at colostrum, 1, 3, 6, 9 and 12 months in ten mothers recruited after delivery of full-term infants. Total saturated fatty acids progressively increase and total monounsaturated progressively decrease as percentage levels, while among long-chain polyunsaturated fatty acids, percentages of arachidonic acid and docosahexaenoic acid decrease from colostrum up to the third month. Hindmilk total lipids (mg/dl) rise more than twofold up to 3 months, and then remain stable. The amounts (mg/dl) of linoleic acid and α-linolenic acid progressively increase, following the trend of total fat, while arachidonic and docosahexaenoic concentrations (mg/dl) remain stable throughout the whole nursing period. Assessment of the intakes per kg body weight shows different trends for the individual major long-chain polyunsaturated fatty acids supplied to the infant from hindmilk during exclusive breast-feeding (3 months). This information may be useful for the evaluation of infant intakes during extended lactation.


1969 ◽  
Vol 52 (4) ◽  
pp. 685-688
Author(s):  
John L Iverson ◽  
P G Harrill ◽  
Robert W Weik

Abstract This proposed urea fractionation procedure concentrates esters with similar GLC retention times in separate fractions. GLC peaks of esters present in cocoa butter oil in trace amounts (0.001–0.1%), which are normally hidden under major peaks, can then be detected. By modified programmed temperature GLC techniques, it is possible to detect the short and long chain length fatty acids present in cocoa butter oil. The odd and even chain length saturated acids from C10 to C28, mono-unsaturates C16 to C24, branched acids C16 to C24, and linoleic and linolenic acids were detected.


1996 ◽  
Vol 315 (1) ◽  
pp. 329-333 ◽  
Author(s):  
Danielle MARTIN ◽  
Kelly A. MECKLING-GILL

Here we show that in vitro supplementation of L1210 murine lymphoblastic leukaemia cells with n-3 polyunsaturated fatty acids results in considerable changes in the fatty acid composition of membrane phospholipids. Incubations for 48 h with 30 μM eicosapentaenoic acid (20:5, n-3; EPA) or docosahexaenoic acid (22:6, n-3; DHA) results primarily in substitution of long-chain n-6 fatty acids with long-chain n-3 fatty acids. This results in a decrease in the n-6/n-3 ratio from 6.9 in unsupplemented cultures to 1.2 or 1.6 for EPA and DHA supplemented cultures, respectively. Coincident with these changes in membrane fatty acid composition, we observed a 5-fold increase in the rate of adenosine (5 μM) uptake via the nitrobenzylthioinosine (NBMPR)-sensitive nucleoside transporter in EPA- and DHA- supplemented L1210 cells, relative to unsupplemented cells. This seemed to result from a decrease in the Km for adenosine from 12.5 μM in unsupplemented cultures to 5.1 μM in DHA-treated cultures. Guanosine (50 μM) transport was similarly affected by DHA with a 3.5-fold increase in the initial rate of uptake. In contrast, pyrimidine transport, as measured by uptake of thymidine and cytidine, was not similarly affected, suggesting that substrate recognition had been altered by fatty acid supplementation. Studies using [3H]NBMPR showed that there was no effect of EPA or DHA on either the number of NBMPR-binding sites or the affinity of these sites for NBMPR. This observation suggests that the increases in adenosine and guanosine transport were not due to increases in the number of transporter sites but rather that EPA and DHA directly or indirectly modulate transporter function.


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