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Utilization of fats and fatty acids by turkey poults.

Two experiments were carried out with young, Large White male turkey poults maintained in either floor pens or metabolism cages. In Experiment 1, poults were fed isoenergetic diets containing either no supplemental fat, or 5% of either tallow, corn oil, soybean oil, animal-vegetable blend fat, or canola oil. Poults generally ate less of the fat-supplemented diets and showed improved feed utilization, although weight gain was little affected. There was improved fat retention when vegetable oils were used (P < .01) and this was reflected in a slight improvement in diet energy level (P > .05). Poults fed tallow or animal-vegetable blend fat also excreted most fat. Diet had no effect (P > .05) on apparent retention of calcium or phosphorus, although retention of magnesium was less with more saturated fats. In Experiment 2, poults were fed diets containing palmitic acid, oleic acid, or a 50:50 (wt/wt) mixture of these fatty acids. There was a reduction (P < .05) in apparent retention of nitrogen, magnesium, calcium, and fat for poults fed palmitic acid, oleic acid, or the mixture. Mixing palmitic acid with oleic acid corrected some of these problems. However, reduced mineral retention was not reflected in any change in levels of bone ash, calcium, or phosphorus. Feeding palmitic acid did result in the most dramatic reduction of bone magnesium content (P < .05). It is concluded that turkey poults, like chicks, are less able to digest saturated fatty acids, and that such undigested fats can lead to reduced retention of some minerals through increased soap formation. However, there is no direct evidence that such soap formation causes a major change in bone calcium or phosphorus content or in gross bone development or poult well-being.

Animals↗

The resolution of racemic hydroperoxides: a chromatography-based separation of perketals derived from arachidonic, linoleic, and oleic acid hydroperoxides.

In spite of the importance of optically pure unsaturated hydroperoxides in biology, chemistry, and medicine, no general method for synthesizing these labile compounds has been reported. We have developed a chiral vinyl ether that reacts with racemic hydroperoxides to give diastereomeric perketals in high yield. These perketals can be separated by liquid chromatography and the chiral group removed to provide highly enriched hydroperoxide enantiomers (greater than 99% enantiomeric excess). The chiral reagent that has been most successful in our hands is the 2-propenyl ether derived from trans-2-phenylcyclohexanol. By use of this vinyl ether, perketals are readily formed from hydroperoxides, they are stable to normal- and reverse-phase chromatography, and the hydroperoxide is regenerated from the perketal without racemization in high yield with mild acid. Several chiral hydroperoxides have been resolved by this procedure: alpha-phenethyl hydroperoxide, 2-octyl hydroperoxide, and a number of hydroperoxides derived from oleic, linoleic, and arachidonic acids.

Chromatography, Liquid↗

Effects of duodenal infusions of palmitic, stearic, or oleic acids on milk composition and physical properties of butter.

Four dairy cows fitted with a duodenal cannula were used in a 4 x 4 Latin square design to investigate the effects of daily duodenal infusion of 500 g of fatty acids (containing mainly C16:0, C18:0, or cis-C18:1) on fecal concentrations of fatty acids, fatty acid profiles of milk fat, and solid fat content of butter. Fecal concentrations of C16:0 and especially of C18:0 were increased by duodenal infusion. Infusion with C16:0 increased the proportion of C16:0 in milk fat and delayed softening of butter when the temperature rose. Infusion with C18:0 resulted only in a slight increase of C18:0 proportion in milk fat and did not significantly affect solid fat in butter between -10 and 30 degrees C. With the infusion of cis-C18:1, the proportion of cis-C18:1 in milk fat was more than twice that of control, to the detriment of C16:0. Butter contained low proportion of solid fat, even at low temperatures. Increasing C16:0 or cis-C18:1 in milk fatty acid via duodenal infusion can be used to study their specific effects on butter characteristics, but, because of a low transfer from infusion to milk, this method is less efficient with C18:0.

Animals↗

Effect of ricinoleic acid and other laxatives on net water flux and prostaglandin E release by the rat colon.

Ricinoleic acid, oleic acid, dioctyl sodium sulphosuccinate, deoxycholic acid, sennoside A + B and mannitol reduced or reversed water flux from lumen to blood in rat colon in situ. Stearinic acid was without any effect. Ricinoleic acid, oleic acid, dioctyl sodium sulphosuccinate, deoxycholic acid and sennoside A + B stimulated release of PGE-like material into the colonic lumen whereas the osmotic laxative mannitol and stearinic acid did not. Inhibition of PGE biosynthesis by pretreatment of the rats with indomethacin significantly reduced (but did not abolish) the effect of ricinoleic, oleic and deoxycholic acids on net water flux and PGE release. Indomethacin reduced the effect of dioctyl sodium sulphosuccinate and of sennoside A + B on PGE release but not their effect on the net water flux. The effect of mannitol was not influenced by indomethacin. The amount of PGE release in experiments with ricinoleic acid, oleic acid, stearinic acid and dioctyl sodium sulphosuccinate (with and without indomethacin) showed a good correlation (r = 0.99) with the change in net water flux. Deoxycholic acid, sennoside A + B and mannitol did not show this correlation. It is assumed that the action of non-osmotic laxatives is partially mediated by PGE, although other mechanisms also seem to be involved in their mode of action.

Animals↗

Acyl chain dynamics of phosphatidylethanolamines containing oleic acid and dihydrosterculic acid: 2H NMR relaxation studies.

The dynamical behavior of the acyl chains of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine, and 1-palmitoyl-2-dihydrosterculoyl-sn-glycero-3-phosphoethanolamine has been investigated by using 2H T1 and T2 relaxation times. Lipids were labeled at the 5-,9-,10-, and 16-positions of the sn-2 acyl chain. The profile of deuterium spin-lattice relaxation rate (T1(-1) vs. chain position is characterized in all systems by a marked discontinuity at the positions of the carbon-carbon double bond and the cyclopropane ring; the deuterons at these positions have relaxation rates which are greater than at any other labeled position of the sn-2 chain. For both types of sn-2 acyl chain, assuming a single-exponential correlation time and that the motion is within the rapid regime, the phosphatidylcholine lipid systems are less mobile than their phosphatidylethanolamine analogues. Systems containing an oleoyl chain are more dynamic than their analogues containing a dihydrosterculoyl chain. The rates of motion of the sn-2 acyl chains of phosphatidylethanolamine in a bilayer structure are slower than those of the lipid in an inverted hexagonal structure. In the hexagonal phase, the motional rates of a dihydrosterculoyl chain are slower than those of the corresponding positions of an oleoyl chain.

Fatty Acids↗

Thermotropic phase behavior of model membranes composed of phosphatidylcholines containing cis-monounsaturated acyl chain homologues of oleic acid: differential scanning calorimetric and 31P NMR spectroscopic studies.

The thermotropic phase behavior of dioleoylphosphatidylcholine and six of its longer chain homologues was studied by differential scanning calorimetry and 31P nuclear magnetic resonance (NMR) spectroscopy. Aqueous dispersions of these compounds all exhibit a single endotherm upon heating but upon cooling exhibit at least two exotherms, both of which occur at temperatures lower than those of their heating endotherm. The single transition observed upon heating was shown by 31P NMR spectroscopy to be a net conversion from a condensed, subgel-like phase (Lc phase) to the liquid-crystalline state. Aqueous ethylene glycol dispersions of these compounds also exhibit single endotherms upon heating and cooling exotherms centered at temperatures lower than those of their corresponding heating endotherm. However, the behavior of the aqueous ethylene glycol dispersions differs with respect to their transition temperatures and enthalpies as well as the extent of "undercooling" observed, and there is some evidence of discontinuities in the cooling behavior of the odd- and even-numbered members of the homologous series. Like the aqueous dispersions, 31P NMR spectroscopy also shows that the calorimetric events observed in aqueous ethylene glycol involve net interconversions between an Lc-like phase and the liquid-crystalline state. However, the Lc phase formed in aqueous ethylene glycol dispersions exhibits a considerably broader powder pattern than that observed in water. This, together with the fact that the transition enthalpies of the aqueous ethylene glycol dispersions are considerably higher than those of the aqueous dispersions, indicates that these lipids form more ordered Lc phases in aqueous ethylene glycol.(ABSTRACT TRUNCATED AT 250 WORDS)

Calorimetry, Differential Scanning↗

Effects of a protein meal, intraduodenal HCl, and oleic acid on portal and peripheral venous secretin and on pancreatic bicarbonate secretion.

We have studied the effect of a protein meal on secretin (IRS) concentration in dogs and humans using a radioimmunoassay of improved sensitivity (8 pg/ml). After a meal, pancreatic bicarbonate secretion (PBS) increased markedly and proximal duodenal pH decreased from 6.2 to 4.3. Portal and peripheral IRS concentrations, however, remained unchanged in eight dogs and five patients with cirrhosis of the liver. Similarly, an alkaline solution of sodium oleate (pH 9.2) stimulated PBS but not IRS. Intraduodenal administration of various amounts of HCl in dogs demonstrated that acid-stimulated PBS was invariably accompanied by rises in peripheral venous IRS concentration. We conclude that the postprandial stimulation of PBS involves mechanisms more complex than acid-stimulated secretin release.

Adult↗