ISSN : 1301-5680
e-ISSN : 2149-8156
Turkish Journal of Thoracic and Cardiovascular Surgery     
A comparison of the vasodilatory effects of verapamil, papaverine and nitroglycerin on isolated rat aorta
Turan Ege1, Ümit Halıcı1, Özcan Gür2, Selami Gürkan2, Demet Özkaramanlı Gür3, Enver Duran1
1Department of Cardiovascular Surgery, Medical Faculty of Trakya University, Edirne, Turkey
2Department of Cardiovascular Surgery, Medical Faculty of Namık Kemal University, Tekirdağ, Turkey
3Department of Cardiology, Tekirdag State Hospital, Tekirdağ, Turkey
DOI : 10.5606/tgkdc.dergisi.2013.7870
Background: This study aims to compare the vasodilatory effects of verapamil, papaverine and nitroglycerin on rat aortic preparations in in vitro isolated tissue bath system and to evaluate the role of vascular endothelium on vasodilatory responses of the isolated rat aorta samples.

Methods: The thoracic aorta segments collected from 30 male Wistar rats (20 endothelialized and 20 de-endothelialized vascular rings for each drug in 2 mm wide strips, total number of 120 vascular rings) were suspended into the Krebs solution of the isolated tissue bath system. Phenylephrine was used to induce isometric contraction and tissue samples were treated with verapamil, papaverine and nitroglycerin separately to draw concentration-response curves of isometric vasodilatory responses. This procedure was repeated for de-endothelialized aorta samples.

Results: Papaverine and verapamil induced vasodilatatory responses starting from the concentration of 10-8 M and reached its maximum at concentration of 10-3 M, while nitroglycerin induced vasodilation at lower concentrations starting from a concentration of 10-12 M, reaching its maximum at 10-6 M. Nitroglycerin was the most potent agent, followed by verapamil and papaverine. Efficacy analysis revealed that the most efficient agents were papaverine (140±6.7%), nitroglycerin (110.8±1.35%) and verapamil (99±4.14%), respectively. The results were similar in aorta samples without endothelium (p≥0.05, F test).

Conclusion: In this study examining isolated rat aorta, nitroglycerin was the most potent agent, while papaverine was the most efficient agent. Our study results showed that endothelium played no role in vasodilatation responses of these drugs.

Keywords : Aorta; nitroglycerin; papaverine; vasodilatation; verapamil
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