C. A. Denton

Absorption of vitamin B12 from the cecum of the hen.

Summary 1. Cecectomy did not shorten the time required to deplete the egg of vit. B12 when the hen was fed a corn-soybean meal type diet deficient in the vitamin. Thus it appears that the hen on a deficient diet does not derive any appreciable benefit from the B12 present in the ceca. 2. Following injection of Co-60 labeled vit. Bi2 into the occluded cecum of the hen7 small amounts of radioactivity, chromatographically similar to B12 were found in the tissues. The data indicate that this B12 was absorbed as the free vitamin and that the Bi2 retained in the cecum became bound. It is suggested that the vit. B12 normally present in the ceca of the hen is essentially unavailable for absorption. 3. When S-35 labeled methionine or sodium sulfate was injected into the cecum an average of 93 and 96%, respectively, of the dose was absorbed within 48 hours. Studies on the uptake of these 2 compounds in the blood show that they were rapidly absorbed.

The vitamin B12 activity of eggs and some materials as affected by extraction in the presence of sodium cyanide or sodium bisulfite

Abstract The B 12 activity of eggs, estimated by microbiological assay, was increased fourfold by the use of sodium cyanide in the extraction mixture. Cyanide also permitted the recovery of added crystalline B 12 . Sodium bisulfite appeared to be as effective as cyanide. Both of these compounds enhanced the apparent B 12 activity of eggs, day-old chicks, and the cecal contents of the hen, but were without effect in the assay of hens liver, fish meal, and meat meal, or a fraction from cow manure.

Tryptophan-niacin relationship in the developing chick embryo☆

Abstract The injection of tryptophan in the egg after 10 days of incubation resulted in a significant increase in the niacin content, but no increase in the tryptophan content of the newly hatched chick. The injection of niacin had no sparing effect on tryptophan and only a small part of the injected material could be recovered from the chick. The niacin content increases in the incubating egg and the tryptophan content decreases. Anthranilic acid and 3-hydroxyanthranilic acid injections did not increase the niacin content of the chick. The injection of pyridoxine and pyridoxamine together with tryptophan did not increase the niacin content of the chick above that resulting from tryptophan alone. A consistent, but not statistically significant, decrease in the niacin content of the chick resulted from the injection of desoxypyridoxine.

Retention of Co 60 Labeled Vitamin B12 in Chickens.

Summary The results indicate that over 30% of the injected Co 60 activity is retained for as long as 12 weeks in chicks hatched from eggs injected with the radio-vitamin. The total B12 content of the chick as measured microbiologically roughly parallels Co 60 activity until 6 weeks of age, after which there is a decided increase in the total B12 content of the chicks.

Feather depigmentation resulting from feeding molybdenum plus thiosulfate.

Summary These experiments show that addition of molybdenum plus thiosulfate will cause feather depigmentation in growing chicks. Supplementation of the diet with vitamins or lysine did not prevent feather depigmentation when the diet contained molybdenum and thiosulfate. No feather depigmentation occurred if copper (50 ppm) was added to the diet. Chicks having feather depigmentation had higher copper, molybdenum and sulfur35 content in liver tissues than the basal group or groups receiving supplementary thiosulfate or molybdenum. In all groups fed radioactive sodium thiosulfate, radioactivity was found in the taurine fraction but not in methionine or cystine fraction of liver hydrolysates.

Chemically Induced Degeneration of Chick Mesonephros.

Summary In an experiment on the toxicity of various chemicals on developing chick embryos it was demonstrated that the kidneys of 10- and 15-day embryos were severely damaged by injections of various chemicals. The kidneys of older embryos, those of day-old chicks, and those of control embryos of various ages treated with distilled water gave no evidence of kidney degeneration. From the experiment it appears that the chemical substances injected had a toxic effect on the mesonephros but not on the metanephros.

Apparent loss of glycine on acid hydrolysis.

Summary An apparent loss of glycine with increasing time of acid hydrolysis has been described. Short-term hydrolysates contain glycine peptides which largely disappeared as time of hydrolysis was extended. Lowering the concentration of amino acids in the basal medium resulted in disappearance of this apparent loss of glycine. With such a modified medium, a number of feedstuffs have been assayed for glycine.

Metabolism of C14-labeled tryptophan in the developing chick embryo☆

Abstract Between 44 and 47 % of the labeled tryptophan injected into the egg was recovered, as such, in the protein fraction of the newly hatched chick. A significant amount of the C 14 from tryptophan-2-C 14 was recovered as alanine and a much smaller amount as glycine. The distribution of radioactivity in the chick following injection of tryptophan-2-C 14 or tryptophan3-C 14 is discussed. Direct confirmation is presented for the conversion of tryptophan to niacin (nicotinic acid) by the chick embryo.