R. EMILOVA1, D. DIMITROVA2, V. GEORGIEV1, T. DANEVA3 and H. S. GAGOV11 Sofia University “St. Kliment Ohridski”, Dept. Animal and Human Physiology, Faculty of Biology, BG – 1164 Sofia, Bulgaria
Emilova, R., D. Dimitrova, V. Georgiev, T. Daneva and H. S. Gagov, 2013. Cystathionine gamma–lyase as a regulator of resistance artery contraction under normal and hyperglycemic conditions. Bulg. J. Agric. Sci., Supplement 2, 19: 175–177
The aim of our study is to clarify the contribution of cystathionine gamma–lyase (CSE) that produces H2S in smooth muscle and perivascular adipose tissues in the regulation of resistance size rat artery contraction. In this research the isometric contraction of de-endothelised rat gracilis artery preparations was measured with Small Vessel Myograph (DMT 410M, Denmark). Half of the isolated rings were incubated in 20 mmol/l D-glucose-containing bath and the others in normal glucose solution (5.5 mmol/l). Increasing concentrations of serotonin (5-hydroxytryptamine) from 10–10 to 10–5 mmol/l were applied to induce gradual constriction of circular artery segments. The absence of endothelium was confirmed by the lack of the relaxation to acetylcholine. The extra cellular glucose concentration of 20 mmol/l did not influence the contractile effect of serotonin. The inhibition of CSE by DL-propargyl glycine significantly enhanced the maximal force of serotonin-induced contraction under normal and hyperglycemic conditions. It is concluded that CSE is an important regulator of endothelium denuded rat resistance arteries. It is suggested that CSE in smooth muscle cells of artery wall released mediator that antagonized the constricting action of serotonin. This regulation is insensitive to extra cellular glucose concentration.