Search PubMed⌕ Search

Biomedical subjects

F E Putilina

Publications and source records attributed to F E Putilina.

24 records · Page 2Linked to original sources
PubMedDate not supplied

The effects of thyroxine isomers on free-radical oxidation processes in subcellular fractions of rat cerebral cortex.

Measurements made by chemiluminescence (CL) were used to estimate effective D- and L-thyroxine concentrations and to study their effects on free-radical oxidation processes in the mitochondrial and synaptosomal fractions of rat cerebral cortex in vitro. These experiments showed that in a model system containing riboflavin, the antioxidant activity of D-T4 was 2.2 times greater than that of L-T4. The effective concentrations for the two forms of thyroxine were I50 = 74.3 +/- 7.1 microM for D-T4 and I50 = 154.7 +/- 12.3 microM for L-T4. Studies of the in vitro effects of thyroxine on the membrane fraction of the cerebral cortex were based on luminol-dependent peroxide CL. At physiological concentrations (10 nM), both isomers of the hormone had identical antioxidant activities, which were stronger in the mitochondrial traction, where the intensity of CL decreased by 69% and 66%, compared with 45% and 46% decreases in the synaptosomal fraction. Since the D-form has no hormonal activity, it is suggested that this effect is associated with the phenolic nature of thyroxine.

Animals↗
PubMedDate not supplied

[Change in the activity of NAD- and NADP-specific malate dehyrdogenases in oxygen deficiency in different tissues].

NAD-dependent malate dehydrogenase (1.1.1.37) activity was markedly decreased under hypoxia in rat brain and liver mitochondria and cytoplasm; most significant decrease was observed in brain cortex mitochondria. NADP-dependent malate dehydrogenase (1.1.1.40) activity was also reduced under these conditions and the most considerable changes were found in liver mitochondria and cytoplasm. Distribution of activities of these enzymes between subcellular fractions of brain and liver did not change under hypoxia. The oxaloacetate level rised by 20% in brain and decreased by 20-25% in liver under hypoxia.

Animals↗
PubMedDate not supplied

[Use of different precursors of fatty acid biosynthesis in the brain in chronic hyperphenylalaninemia].

The incorporation of 14C from 2-14C-acetate, 1-6-14C-glucose and 5-14-C-glutamate into fatty acids of brain lipids under chronic hyperphenylalaninemia (HPA) was investigated. A decrease of lipogenesis intensity was demonstrated in young rat brain. In the HPA a decrease in the labelling of fatty acids occurred due to inhibition of the enzymes of fatty acid biosynthesis and to disturbance of metabolic pathways involved in lipogenesis via acentyl-CoA.

Acetates↗
PubMedDate not supplied

[Disruption of nerve tissue cholesterol metabolism in the case of an excess of vitamin A in the growing body].

Subcellular distribution and the rate of labelled precursors incorporation into fractions of cholesterol esters were studied in brain and spinal cord of growing rats consuming overdoses of vitamin A. Per os administration of retinyl acetate during 10-16 days of postnatal period at a dose of 1,000 IU resulted in intracellular imbalance of cholesterol content and in distinct increase of cholesterol esters in all the subcellular fractions studied. A decrease of 2-(14)C- acetate incorporation into cholesterol esters of nervous tissue caused by vitamin A overloading was also detected. Analysis of gas chromatograms showed an increase in content of palmitic acid as well as a decrease of unsaturated acids in fractions of cholesterol esters of these animals brain tissues. The impairments of cholesterol metabolism found in nervous tissue of growing body under conditions of retinol overloading may be responsible for deterioration of myelinization.

Animals↗