The mechanism by which palmitic and oleic acids modify calcium sequestration by sarcoplasmic reticulum vesicles was investigated by examining the effects of these fatty acids on calcium -dependent ATPase activity, on the phosphoenzyme intermediates found during calcium sequestration reactions, and on passive membrane permeability to calcium. The calcium sequestered in the presence of these fatt...

Incubation of rat brain myelin with [3H]palmitic acid in the presence of ATP, CoA and MgCl2 or [14C]-palmitoyl-CoA in a cell-free system resulted in the selective labelling of 'PLP' [proteolipid protein; Folch & Lees (1951) J. Biol. Chem. 191, 807-817] and 'DM-20' [Agrawal, Burton, Fishman, Mitchell & Prensky (1972) J. Neurochem. 19, 2083-2089] which, after polyacrylamide-gel electrophoresis in...

Milk fat globule size is determined by the size of its precursors-intracellular lipid droplets-and is tightly associated with its composition. We examined the relationship between phospholipid composition of mammary epithelial cells and the size of both intracellular and secreted milk fat globules. Primary culture of mammary epithelial cells was cultured in medium without free fatty acids (cont...

−− The synthesis of ethyl hexadecanoate was carried out by esterification of palmitic acid with ethanol in a solvent-free system. A commercial immobilized lipase (Lipozyme RM-IM) was mixed with the reagents, in a 15 mL closed batch reactor with constant stirring and coupled with a condenser. The effects of palmitic acid/ethanol molar ratio (0.16 to 1.84), reaction temperature (65 to 75C) and en...

1. Rats were fed to appetite on a stock laboratory diet or on diets consisting of the stock diet and in addition 50 or 200 g triolein/kg, 50 g palmitic acid/kg or 50 g/kg of a concentrate mixture of methyl branched-chain fatty acids (Me-BCFA) which had been prepared from sheep adipose triacylglycerols. 2. No differences could be detected in the delta 9-desaturase activity or fatty acid syntheta...

BACKGROUND/AIMS Elevated levels of non-esterified fatty acids (NEFAs) are under suspicion to mediate β-cell dysfunction and β-cell loss in type 2 diabetes, a phenomenon known as lipotoxicity. Whereas saturated fatty acids show a strong cytotoxic effect upon insulin-producing cells, unsaturated fatty acids are not toxic and can even prevent toxicity. Experimental evidence suggests that oxidative...

The effects of chloroacetaldehyde (CAA) and methylene blue, both alone and together, on mitochondrial metabolism, hepatic glutathione content, and bile flow were investigated in rats. Oxidation of [1-14C]palmitic acid, [1-14C]octanoic acid, and [1,4-14C]succinic acid allowed for the differentiation between carnitine-dependent long-chain fatty acid metabolism, medium chain fatty acid oxidation, ...

Unlike other saturated fatty acids, dietary stearic acid does not appear to raise plasma cholesterol. The reason for this remains to be established, although it appears that it must be related to inherent differences in the metabolism of the fatty acid. In the present study, we have looked at the metabolism of palmitic acid and stearic acid, in comparison with oleic acid, by cultured hamster he...

The expression and function of the GH receptor is critical for the actions of pituitary GH in the intact animal. The role of systemic factors in the reduced expression of the GH receptor and consequent GH insensitivity in pathological states such as sepsis, malnutrition, and poorly controlled diabetes mellitus is unclear. In the current study, we demonstrate that saturated (palmitic and myristi...

Fatty acid synthesis by subcellular fractions of rabbit lung was studied by measuring the incorporation of either radioactive acetyl coenzyme A or malonyl coenzyme A into long-chain fatty acids. Evidence is presented to support the conclusions that the 95,000 g-supernatant fraction contains the enzymes, i.e., fatty acid synthetase and acetyl coenzyme A carboxylase, necessary for de novo fatty a...