Kesten and silbowitz (1) noted that the level of plasma cholesterol was decreased in rabbits fed high levels of lecithin together with cholesterol. Lecithin has also been reported to lower serum cholesterol levels in man (2). It has been shown by Best et al. (3) that the active component of lecithin is choline. Kritchevsky et al. (4) have observed a lowering of serum cholesterol in rabbits after the injec tion of choline citrate. Harrill et al. (5) observed a lowering of cholesterol con tents in the liver of albino rats fed a high fat diet containing high level of ribo flavin. This method of decreasing cholesterol is of considerable interest in the study of arteriosclerosis and deserve further study. Since catabolism of cholesterol consists primarily in the conversion of bile acid (6) and appreciable amount of cholesterol is excreted in the feces, it was thought worthwhile to investigate whether or not choline and riboflavin will influence the fecal excretion of bile acid and cholesterol of animals kept on high cholesterol diet.

No abstract

The incorporation experiments with labeled serine in the crude microsomal protein fraction of normal and thiamine deficient rat liver were carried out. The liver microsomal fraction of animals kept on the thiamine deficient diet showed less incorporation of lebeled serine than the normal animals.The injection of thiamine in the thiamine deficient animals two hours before killing increased to an appreciable extent the incor poration of labeled serine in microsomal protein, indicating a possible role of thiamine in protein biosynthesis. Mulgaonkerr and Sreenivasan (6) observed that in a deficiency of vitamin B12 and folic acid in rats there is a significant reduction in total serum proteins.Raskin and Kirzhner (7) reported that patients receiving vitamin Bs and B12 showed more rapid return to normal in serum protein than the patients not receiving vitamin B6 and B12. These studies indicate clearly that besides vitamin B12 there are other vitamins of B groups which may influence protein synthesis.Since much work has not been carried out on the effect of thiamine on microsomal incorporation of labeled amino acid, it has been thought worth-while to investigate whether thiamine has any in fluence on the microsomal biosynthesis of protein. EXPERIMENTALSixty male albino rats weighing between 40 to 50g were selected for this experiment.The animals were divided into two groups o£ thirty each. The animals of group I were fed a normal diet and the animals of group II were given thiamine deficient diet. The composition of the diet for group I and group II is shown in Table 1. The pair-feeding techniques were followed in feeding the animals. The animals were weighed weekly. The normal and thiamine deficient animals were killed periodically by decapitation. The thiamine content of different tissues was estimated by the method of Harris and Wong (8). The blood pyruvic acid was estimated according to the method of Klein (9). The results are shown in Tables 2 and 3.

No abstract

Protein biosynthesis, using 14C-serine and related aspects in pyridoxine deficient rats were studied. The following results were obtained.