PP.42.20: INFLUENCE OF HYDROGEN SULFIDE ON VOLUME-DEPENDENT CONTRACTILE RESPONSES. (June 2015)

• Record Type: Journal Article
• Authors: Gusakova, S.; Smagliy, L.; Kovalev, I.; Medvedev, M.
• Is Part Of: Journal of hypertension. Volume 33(2015)Supplement 1
• Publication Date: 2015-06
• Subjects: Hypertension -- Periodicals; Hypertension -- Periodicals; 616.132005
• DOI: 10.1097/01.hjh.0000469013.56256.4a
• Languages: English
• ISSNs: 1473-5598

Abstract

Abstract : Objective: Hydrogen sulfide (H2S) plays an important role in modulation of the contractile activity of vascular smooth muscle cells (VSMC). A special case of the VSMC contractile responses is an increase/decrease in cell volume, which largely determines the physiological or pathophysiological status of vessels and visceral organs. We investigated the effect of H2S on the volume-dependent contractile responses, which to date remains little studied. Design and method: The study was performed with the method of mechanography using endothelium-denuded aortic ring segments of male Wistar rats. Contractions were induced with high potassium solution (30 mM KCl), hyper- (150 mM sucrose), hypo- (40 mM NaCl) and iso-osmotic solutions (120 mM NaCl). We used NaHS as hydrogen sulphide donor. Results: In the case of hyperosmotic striction addition of 10 mM NaHS led to a further increase in mechanical tension (MT) to 61.5 ± 7.8% (n = 5, p < 0.05) of the value of the high potassium contraction. 1 mM NaHS relaxes vascular segments, precontracted with 150 mM sucrose to 9.7 ± 2.4% (n = 5, p < 0.05) of the value of the high potassium contraction. In the case of hypnosmotic striction 10 mM NaHS had no statistically significant effect on the value of MT and duration of contractions. In the presence of 1 mM NaHS the value hyposmotic contraction significantly reduced (it was 51.8 ± 12.0% (n = 5, p < 0.05) of the value of the high potassium contraction). The duration of the contractions was not significantly changed. 10 mM NaHS caused a significant increase in the amplitude of isosmotic striction to 37.0 ± 4.3% (n = 9, p < 0.05) of the value of the high potassium contraction, and the duration of the contraction to 64.7 ± 2.9 min (n = 9, p < 0.05). 1 mM NaHS also significantly decreased the value of isoosmotic contraction to 13.8 ± 2.1% (n = 4, p < 0.05) of the value of the high potassium contraction, the duration of the contraction was not significantly changed. Conclusions: Thus, NaHS at low concentrations (10 mM) stimulates an increase in the amplitude of contractile responses of VSMC in a hyper and isoosmotic, but not hypnotonic striction.