Oliynyk, I. | Search bioRxiv

bioRxiv2026

Lactate Dehydrogenase Activity and Carbohydrate Metabolism under Vanadium Citrate Exposure: Sex- and Dose-Dependent Effects in Rat Tissues

Vanadium (V) is a potential insulinomimetic that can modulate carbohydrate metabolism, but its biological effects are sensitive to chemical form, concentration, and sex. Chelation of vanadium with organic ligands, in particular citrate, allows to increase its bioavailability and optimize pharmacokinetic properties. The aim of the study was to evaluate tissue-, dose-, and sex-dependent changes in physiological parameters and activity of the key glycolytic enzyme - lactate dehydrogenase (LDH) - under the influence of vanadium citrate. The study was conducted on 6-week-old Wistar rats of both sexes. The animals received vanadium citrate orally for 36-38 days at doses of 3, 12.5, and 50 g VCit/kg body weight. LDH activity in skeletal muscle, liver, kidney, and pancreas was investigated. No pronounced toxic effect on physiological parameters was detected: body weight dynamics corresponded to age norms, no behavioral changes were observed. LDH activity demonstrated pronounced sexual dimorphism and depended on the dose received. It was established that the optimal dose, which provides a modulating effect without signs of metabolic stress, for females is 12.5 g VCit/kg, while for males - 3 g VCit/kg. The most significant changes in LDH activity were recorded in the pancreas at a dose of 50 g V/kg, where the indicators decreased from 0.81 to 0.31 mol/(min x mg protein) in females and from 1.02 to 0.28 mol/(min x mg protein) in males. The effect of vanadium citrate on carbohydrate metabolism, as well as its dose-, tissue- and sex-specific nature, is likely determined by a dual action: the insulin-like effect of vanadium (redirecting pyruvate to oxidation) and the allosteric inhibition of glycolysis by the citrate ligand (substrate limitation for LDH). The obtained results emphasize the importance of considering sex and dose in the research and development of metabolically active compounds.

biochemistry↗

bioRxiv2024

Possible Mechanisms Of Action Of Light Inert Gases On Chemiluminescence Arising As A Result Of Lipid Peroxidation

The use of inert gases in biology and medicine and their effect on biological objects both in vitro and in vivo remains an active area of research. It has been established that light noble gases affect antioxidant processes, free radical oxidation, and enhance chemiluminescence, but an explanation of the physical and chemical mechanisms of this effect is still lacking and is key to further theoretical and experimental studies, given the broad prospects for the use of noble gases in medicine. In this article, we present two of the possible mechanisms of light inert gases effect on chemiluminescence (CL), a phenomenon that occurs as a result of free radical recombination and chain breakage during lipid peroxidation. Since the effect on oxidation, in turn, precedes the effect on the antioxidant system and the bodys defense mechanisms. One of the mechanisms of influence is based on the ability of inert gases to dissolve well in lipids and dissolve poorly in water. Their ability to dissolve in lipid bilayers and affect the conformation of lipid complexes can increase the surface area available for oxidation, the surface area that absorbs radiation and reduce the density of the environment, potentially increasing the availability of oxygen for oxidation reactions. This is the so-called spatial mechanism of inert gas influence on oxidation and chemiluminescence. The second mechanism is based on the influence on the quantum chemical parameters of the reaction medium. The acceleration of VT relaxation processes, the impact on the components of the medium in quenching excited states, and the radiative decay time of the excited state.

biophysics↗