Author(s)

Burak Cem Soner, Ayse Saide Sahin, Ipek Duman, Niyazi Gormus

.

Aim: Increased oxidative stress plays important roles in vascular dysfunction in patients undergoing coronary artery bypass graft surgery. Hydrogen peroxide (H₂O₂) is used as an experimental model for oxidative stress. The present study was designed to assess the effects of levosimendan pretreatment on the contractile effects induced by H₂O₂ in human saphenous vein (HSV) segments. Methods: We studied H₂O₂ induced contractions of isolated HSV mounted in standard tissue baths. H₂O₂ (10^-6 – 10^-3 M) was added cumulatively to the organ bath. Concentration-response curves to H₂O₂ were repeated in the presence of levosimendan (10^–8 M). In the second series of experiments, strips were contracted with 5-HT (10^–5 M). When the contraction reached a stable plateau, H₂O₂ was administrated cumulatively into the organ bath. The same procedure was conducted in the presence of levosimendan. Results: Pretreatment of the SV strips with levosimendan significantly reduced the contractile response to each concentration of H₂O₂ . 5-HT produced contractions in SV strips. Further treatment of these strips with H₂O₂ resulted in statistically significant concentration-dependent increases in tension. Preincubation of the tissues with levosimendan did not significantly influence the maximum amplitude of the 5-HT-induced tone but inhibited the contractile effect of H₂O₂ on the 5-HT-induced contraction. Conclusion: Pretreatment of HSV with clinical concentrations of levosimendan inhibits the vasoconstriction caused by oxidative stress, indicating its potential preventive effect against oxidative stress induced graft spasm.

Hydrogen Peroxide, Human Saphenous Vein, Levosimendan

B. Soner, A. Sahin, I. Duman and N. Gormus, "Effects of Levosimendan on Hydrogen Peroxide Induced Contraction in Human Saphenous Vein," Pharmacology & Pharmacy, Vol. 2 No. 4, 2011, pp. 233-237. doi: 10.4236/pp.2011.24030.