An experiment was carried out to determine the protective effect of orotic acid (uracil-4-carboxylic acid) against X-rays. Orotic acid in dose of 0.05, 0.1, 1.0, 1.7 and 10 mg per mouse was given intra peritoneally to mice before or after a single dose whole-body X irradiation of 700 r or 550 r, after which the 30-day survival rate was observed. As a result it was concluded that it would be dif...

Orotic acid, first discovered in ruminant milk, is an intermediate in the pyrimidine biosynthesis pathway of animal cells. Its synthesis is initiated by the formation of carbamoyl phosphate (CP) in the cytoplasm, with ammonia derived from glutamine. Ureotelic species also form CP in the first step of urea synthesis in liver mitochondria. For that, ammonia is derived from tissue fluid. When ther...

Aim: Objectives To evalate the differences in metabolic responses between dietary orotic acid and adenine in lipid profi les of serum and liver tissues. Methods: Rats were paired-fed 1.0 % orotic acid (orotic acid group) and 0.25 % adenine (adenine group) diets or a non-supplemented diet (control group) for 10 days. Serum lipid concentrations were measured using enzyme assay kits. Lipids of liv...

The concentration of orotic acid in dry whey ranged between 64 and 146 mg/100 g and appeared dependent on whey type. The orotic acid of modified whey products, prepared commercially by electrodialysis, ultrafiltration, gel filtration, or polyphosphate precipitation was between 7 and 124 mg/100 g, which was less than that of dry whey. It appears that whey processing methods do not concentrate or...

In commonly used procedures for colorimetric assay of orotic acid in biological materials, certain substances interfere, positively or negatively. Some that interfere negatively are ornithine, cysteine, citrulline, tyrosine, proline, hydroxyproline, and polyamines. Protein and interfering agents are easily removed by first isolating the total organic acid fraction. The orotic acid in this fract...

The urinary excretion of orotic acid, an intermediate in the pyrimidine biosynthetic pathway, is markedly increased in many inborn errors of the urea cycle and in a number of other disorders involving arginine metabolism. Carbamoyl phosphate, which accumulates within hepatic mitochondria in patients with ornithine transcarbamoylase deficiency, can diffuse to the cytosol and enter the pyrimidine...

Dietary orotic acid is known to cause impaired fatty acid synthesis and increased cholesterol synthesis in rats. We found that the impaired fatty acid synthesis occurs during the first day of orotic acid feeding and, in studies with albumin-bound [1-14C]palmitic acid, an associated decrease in the rate of esterification of this fatty acid into triacylglycerol, phospholipid, and cholesteryl este...

This study was designed to determine the possible mechanism by which orotic acid exerts its mitoinhibitory effect on rat hepatocytes in primary culture. Orotic acid inhibited, dose-dependently DNA synthesis in hepatocytes induced by epidermal growth factor, transforming growth factor a, hepatocyte growth factor, acidic fibroblast growth factor, or plasma from rats exposed to various liver cell-...

In the course of studying the effect of nucleic acid precursors on viral carcinogenesis it was observed that an increased number of métastasesdeveloped in the lungs of orotic acid-treated mice with spontaneous mammary tumors. Further evidence that orotic acid increases the establishment of lung métastaseswas noted when orotic acidtreated C3H/HeN mice given injections intravenously of a cell s...

The coinparntivc potencies of uracil mid thiouracil in terms of thyroidal changes, hypercholcstcrcinin, azoteniia, and incipient atherosclerosis were determined in rats fed cholesterol and cholic acid. Higher dietary levels of uracil were required to produce changes similar to those seen with thiouracil. Certain dietary components related to uracil were also studied. Orotic acid was found to ha...