Vіsnik Naukovih Doslіdžen' (Apr 2017)
SEX DIFFERENCES IN THE INFLUENCE OF HYPERHOMOCYSTEINEMIA ON HYDROGEN SULFIDE METABOLISM IN THE CARDIOVASCULAR SYSTEM
Abstract
Hyperhomocysteinemia is a well-known and independent risk factor of heart and blood vessels diseases. It is shown that this pathological condition decreases the level of hydrogen sulfide – which is a biologically active substance that is involved in the regulation of vascular tone, myocardial contractility. However, it is unknown the existence of sex differences in the influence of hyperhomocysteinemia on hydrogen sulfide metabolism in the cardiovascular system. The aim of the work – to study the effects of experimental hyperhomocysteinemia on the content of hydrogen sulfide and its metabolism in the myocardium and aorta of rats of different sex. Materials and Methods. The experiments were performed on 40 white laboratory rats of both sexes weighing 220–280 g. The model of long-termed hyperhomocysteinemia was created by intragastric introducing of thiolactone D,L-homocysteine dosed 100 mg/kg in 1 % starch solution 1 time a day during 28 days. The work determined the content of hydrogen sulfide in myocardium and aorta, the utilization rate of hydrogen sulfide in myocardium, and the activity of the enzymes of cystathionine-γ-lyase, cysteine aminotranspherase, thiosulfate sulfur transferase, sulfite oxidase in myocardium and aorta. Results and discussion. Hyperhomocysteinemia is accompanied by gender-specific changes in hydrogen sulfide content in myocardium and aorta of rats: decrease of hydrogen sulfide level in males and females is respectively 31.4 to 43.3 % and 20.0–25.1 % (р<0.05) compared to the control group. Prolonged introduction of thiolactone homocysteine causes more substantial disturbances of hydrogen sulfide metabolism in myocardium and aorta in male animals: increase in the rate of hydrogen sulfide utilization is 36.5 % (compared to 22.5 % in females, р<0.05), decrease in the activity of H2S-synthesizing enzymes is 28.3–49.8 % (against 17.1 to 36.8 % in females, р<0.05) compared to the control group. Conclusion. Introduction of tiolactone homocysteine causes gender-specific changes in hydrogen sulfide metabolism in myocardium and aorta. It is shown that the males demonstrate more pronounced decrease in hydrogen sulfide content, activity of H2S-synthesizing enzymes and mitochondrial sulfotransferase, as well as increase in the rate of exogenous hydrogen sulfide utilization in the cardiovascular system, compared to the control group.
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