Pyrimidine nucleotide fund during exposure to radiation and exercise and some approaches to its correction

The purpose of this study was to investigate the effect of orotic acid (vitamin B13) on the content of pyrimidine ribonucleotides in the liver during combined exposure to radiation and exercise. The study was carried out on male albino rats exposed to a single total gamma-irradiation in a dose of 6 Gy and maximal exercise (treadbane running to capacity). Orotic acid was injected as potassium salt in a dose of 60 mg/kg. Irradiation was conducive to a reduction of the levels of uridyl and cytidyl nucleoside diphosphates (UDP and CDP), specifically, nucleoside triphosphates (UTP and CTP) in rat liver, this being paralleled by an increase of nucleoside monophosphates. During combine exposure to radiation and exercise the maximal physical fatigue boosted the effect of radiation. Therapeutic administration of orotic acid led to a relative normalization of disorders of pyrimidine nucleotide background and of individual forms of uridyl and cytidyl nucleotides. 13 refs