Preservation of adrenoceptor and endothelin receptor mediated vasoconstriction after cold storage of explanted blood vessels for ex-vivo analyses

Purpose: Cold storage of blood vessels is a concern in bypass surgery and in ex vivo pharmacological experiments. We compared adrenoceptor and endothelin receptor-mediated vasoconstriction as well as endothelium-dependent vasodilation before and after 20 h storage in commercial and custom-made vessel storage solutions. Methods: Saphenous veins harvested during coronary artery bypass surgery were analyzed by isometric force measurements in organ baths before and after cold storage for 20 h in HEPES-supplemented Dulbecco's modified Eagle's medium (HDMEM), HEPES-supplemented Krebs-Henseleit solution (HKH), or TiProtec solution. Contractile responses to potassium chloride (KCl), norepinephrine (NE), and endothelin-1 (ET-1) as well as vasodilator responses to acetylcholine (ACh) were evaluated. Results: Storage in HDMEM diminished KCl induced contractile forces to 71% (p=0.002) and NE induced contractions to 80% (p=0.037) with no significant changes with the other solutions. NE induced contractions normalized to KCl were not affected by storage. NE EC50 values were slightly lower (7.1E-8 vs. 7.5E-8, p=0.019) after storage in HKH with no changes after storage in the other solutions. Endothelium-dependent responses to ACh were not affected by storage. ET-1 induced contractions were attenuated after storage in HDMEM (77%, p=0.002), HKH (75%, p=0.020), and TiProtec (73%, p=0.010) with no changes in the KCl-normalized constrictions. ET-1 EC50 values were not affected by storage. Conclusion: Changes in contractility after storage likely reflect malnutrition during cold storage with no specific attenuation of adrenoceptor or endothelin-receptor mediated signal transduction. HKH or TiProtec are equally suitable cold storage solutions for preserving blood vessel function for ex-vivo measurements.