ISSN : 1301-5680
e-ISSN : 2149-8156
Turkish Journal of Thoracic and Cardiovascular Surgery     
Vasorelaxant effects of dobutamine and levosimendan on rat aorta rings
Emre Doğan1, Recep Oktay Peker2, Ali Ümit Yener3, Soner Dönmez4, Osman Gökalp5
1Department of Cardiovascular Surgery, Trabzon Ahi Evren Thoracic and Cardiovascular Surgery Training and Research Hospital, Trabzon, Turkey
2Department of Cardiovascular Surgery, Medical Faculty of Hacettepe University, Ankara, Turkey
3Department of Cardiovascular Surgery, Medical Faculty of Çanakkale Onsekiz Mart University, Çanakkale, Turkey
4Department of Chemistry, Nevşehir Hacı Bektaş Veli University, Faculty of Arts and Sciences, Nevşehir, Turkey
5Department of Clinical Pharmacology, Medical Faculty of Dicle University, Diyarbakır, Turkey
DOI : 10.5606/tgkdc.dergisi.2015.10321
Background: In this experimental study, the vasorelaxant effects of levosimendan and dobutamine on isolated rat thoracic aorta preparations were compared.

Methods: Sixteen Wistar albino type male rats were used. The thoracic aortas were removed carefully and were transferred to petri dishes containing Krebs solution. Aortic rings of approximately 5 mm in length were prepared and placed in the organ bath. Contraction and relaxation forces of the aortic rings were recorded. Contraction response was obtained by applying 10-5M phenylephrine to aortic rings. Subsequently, cumulative doses of levosimendan (10-8M-10-4M) was applied to eight aortic rings and cumulative doses of dobutamine (10-8M-10-3M) was applied to the other eight aortic rings and dose-response curves were recorded. The EC50 and pD2 values were calculated by the computer program named Graph Pad Prisim 4.0. The Mann-Whitney U-test was performed for statistical analysis.

Results: The relaxation response of the aortic rings with levosimendan 10-4M administration was %92.33 while the relaxation response with dobutamine 10-4M administration was %82.48. It did not show a significant difference between both relaxation responses (p=0.059). The EC50 value was calculated as 6.605x10-6M for dobutamine and 5.093x10-5M for levosimendan. The pD2 value was found to be 5.2±0.4 for levosimendan and 4.3±0.2 for dobutamine.

Conclusion: Levosimendan and dobutamine molecules in vitro rat aortic rings have similar vasorelaxant effects.

Keywords : Dobutamine; levosimendan; organ bath; rat aorta; vasospasm
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