The lipid composition of human chylomicrons has been studied using blood collected from normal male volunteers after ingestion of 200 g of butter fat. The concentration of chylomicrons in the blood samples varied widely among 12 subjects but in each case the following lipids were present : triglycerides, diglycerides (probably the 1,2-isomers), monoglycerides, free and esterified cholesterol, t...

The in vivo biosynthesis of lecithin in rats has been studied with the precursors choline-1,2-(14)C, ethanolamine-1,2-(14)C and methionine-CH(3)-(14)C or -CH(3)-(3)H. Lecithin synthesis from choline is rapid in all organs. No sex difference was observed in this pathway. The biosynthesis of lecithin by methylation of phosphatidyl ethanolamine is of quantitative significance in the liver, but not...

The influence of diabetes and insulin treatment on the phospholipid content of R3230AC mammary tumors, a hormonally responsive neoplasm, was studied. Diabetes was induced by administration of streptozotocin 3 days prior to tumor implantation. Protamine zinc insulin, 3 IU/rat twice daily, was administered to tumor-bearing rats for 3 days. Enzymatically dissociated tumor cells from diabetic anima...

The phospholipid distribution and the fatty acid composition of the individual phospholipids were determined for the nucleus and the bileaflet nuclear membrane. The phospholipid to protein ratio (milligram per mg) for the nuclear membrane was 0.45 and lipid phosphorus comprised 65% of the total membrane phosphorus. No significant differences were noted in the phospholipid composition of the nuc...

The microviscosity and fluidity of erythrocyte ghost membranes from lead workers and control subjects was measured by fluorescence polarisation using the fluorophore, 1,6-diphenyl-1,3,5-hexatriene (DPH). Increased lead was associated with a significant decrease in the average microviscosity of resealed and unsealed erythrocyte membranes. Since DPH fluorescence reflects the organisation of lipid...

The phospholipid distribution and the fatty acid composition of the individual phospholipids were determined for the nucleus and the bileaflet nuclear membrane. The phospholipid to protein ratio (milligram per mg) for the nuclear membrane was 0.45 and lipid phosphorus comprised 65% of the total membrane phosphorus. No significant differences were noted in the phospholipid composition of the nuc...

The phospholipid distribution and the fatty acid composition of the individual phospholipids were determined for the nucleus and the bileaflet nuclear membrane. The phospholipid to protein ratio (milligram per mg) for the nuclear membrane was 0.45 and lipid phosphorus comprised 65% of the total membrane phosphorus. No significant differences were noted in the phospholipid composition of the nuc...

The phospholipid distribution and the fatty acid composition of the individual phospholipids were determined for the nucleus and the bileaflet nuclear membrane. The phospholipid to protein ratio (milligram per mg) for the nuclear membrane was 0.45 and lipid phosphorus comprised 65% of the total membrane phosphorus. No significant differences were noted in the phospholipid composition of the nuc...

Cells of the yeast sterol auxotroph GL7 were grown on either ergosterol or cholesterol to mid-logarithmic phase and total membrane fractions prepared. Activities of phospholipid biosynthetic enzymes in the two cell types were determined. The rates of phosphatidyl-ethanolamine-phosphatidyl-choline-N-methyl transferase and acyl-CoA-alpha-glycerol-3-phosphate transcylase were significantly greater...

A synthesis of racemic diether analogues of glyceryl phosphatides is reported which is applicable to unsaturated aliphatic substituents. The "oleyl" diether analogue of phosphatidyl ethanolamine has been synthesized.