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Acta Physiologica 2011; Volume 202, Supplement 684
The Joint Conference (FAMÉ 2011) of the LXXVth Meeting of the Hungarian Physiological Society, XVIth Meeting of the Hungarian Society of Anatomists, Experimental Section of the Hungarian Society for Experimental and Clinical Pharmacology and Hungarian Society for Microcirculation and Vascular Biology
6/8/2011-6/11/2011
Pécs, Hungary
COMPARISON OF ANTIOXIDANT EFFECTS OF HYDROGEN SULPHIDE (H2S) AND SUPEROXIDE DISMUTASE (SOD) IN ISOLATED CAROTID ARTERIES
Abstract number: O52
Solymar1 M., Tanai1 E., Parniczky1 A., Porpaczy1 A., Hamar1 J., Koller1,2 Á.
Aims:
Recent studies suggest that H2S is a potent antioxidant that can improve cardiovascular functions in several diseases, such as myocardial ischemia/reperfusion and infarction. Thus we aimed to compare the antioxidant effect of H2S to the well established effect of SOD on superoxide-induced vasomotor activity elicited by pyrogallol.
Methods:
Carotid arteries (n=36) were isolated from male Wistar rats and their isometric contraction forces were measured (DMT myograph). To induce pre-contraction, 60 mM KCl was used, then the effect of pyrogallol (10-5M) was obtained. Next, the vessels were incubated with H2S (10-4 and 10-5 M) or SOD (120U/ml) for 15 minutes, then vasoconstrictions to pyrogallol were measured again. Superoxide generation by pyrogallol was measured by a spectrophotometer, in control and in the presence of SOD or H2S.
Results:
In isolated arteries, KCl induced substantial vasomotor tone (6.9±0.7mN). Additional administration of pyrogallol further increased the vasomotor tone (9.7±0.8mN). In the presence of SOD pyrogallol did not elicit contraction (5.3±0.8mN). Presence of 10-5 M H2S did not affect the vasomotor response to pyrogallol (9.1±0.5mN), whereas 10-4 M H2S reduced the contractions significantly (8.1±0.7mN p<0.05). Also, SOD abolished pyrogallol-induced superoxide production (pyrogallol: A420= 0.19±0.0; pyrogallol+SOD: A420=0.02±0.0 p<0.05). In contrast, H2S (10-5M) did not reduce pyrogallol-induced superoxide production (A420=0.18±0.0), whereas H2S (10-4M) reduced it significantly (A420=0.15±0.0 p<0.05).
Conclusion:
In the present study, in carotid arteries only a very high concentration of H2S (10-4M) elicited partial reduction of superoxide production and contraction to pyrogallol, whereas SOD completely abolished superoxide related effects. Thus it seems that H2S is a less effective antioxidant than SOD, and we suspect that the previously described beneficial effects of H2S on various vascular functions are likely to be mediated not only by its antioxidant activity but by additional mechanisms, as well.
Support:
AHA-FA 0855910D, OTKA K71591 and K67984
To cite this abstract, please use the following information:
Acta Physiologica 2011; Volume 202, Supplement 684 :O52