the effect of various amount of soybean lecithin replaced with egg yolk to protect the ram semen in times of one hour after semen collection, as well as 24 and 48 hours after the semen store at 5°c was evaluated. semen was collected weekly for 8 weeks from 10 rams with 2-3 years old and average body weights of 64 kg. semen samples were pooled and divided into 4 parts. each part was diluted with...

n-/3-Hydroxybutyrate dehydrogenase is a lipid-requiring enzyme which has an absolute requirement for lecithin for enzymic activity. We have studied the activation of the purified apodehydrogenase by a number of lecithin analogues with modifications in either the hydrophobic or polar regions of the molecule in order to map the structural specificity for the lecithin molecule. The apodehydrogenas...

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...

When pure individual synthetic lecithins became available for study (Baer and Kates, 1949, 1950), there was immediate interest in their possible use in cardiolipin antigens as substitutes for Pangborn lecithin. Rosenberg (1949) reported briefly on synthetic L-c-(dipalmitoyl)-lecithin in antigens for the Hinton, Kline, Rein-Bossack, VDRL, and Kolmer tests. He found that replacement of Pangborn's...

The solubilization of glucose and several related sugars in benzene solutions of rigorously purified phosphatidylcholine has been studied; the equilibrium degree of solubilization has been found to depend on the size of the sugar molecule relative to that of the lecithin micelle, and on the number and the acidity of its free hydroxyl groups. The uptake of glucose increased as the lecithin conce...

Cardiolipin antigens, used in the sero-diagnosis of syphilis, are mixtures of the phospholipids, cardiolipin, and purified natural lecithin (beefheart or egg), and usually also contain cholesterol. In 1949 Baer and Kates (1949, 1950) succeeded in the synthesis of L-ac-dimyristoyl lecithin and in the following years other types of synthetic lecithin were produced, including a D-oc-dimyristoyl le...