Functional assessment of rat aorta after cold storage in different media

Cold storage is frequently used to store isolated blood vessels for a limited period of time. However preservation of vascular smooth muscle and endothelial functions is time and medium-dependent. The present study was designed to compare the reactivity of rat aorta before and after cold storage for 24 and 48 h in one of four different solutions consisting of Hepes-buffered Krebs solution, Belzer solution, Krebs solution, and Eurocollins solution. Smooth muscle and endothelial functions of the rat aorta were assessed using in vitro isometric tension measurement. The results obtained for vessels preserved for 24 and 48 h were compared with those for vessels studied immediately after harvesting. Sensitivity and maximum contraction to KCl and norepinephrine were not altered in rat aorta preserved up to 48 h in Hepes-Krebs and Belzer solutions. In contrast, the amplitude of contraction elicited by KCl was significantly reduced by 50% and 77% in aorta stored for 24 and 48 h in Krebs solution and by 77% and 96% in those stored in Eurocollins solutions. Similarly, the maximal contraction elicited by norepinephrine was significantly reduced by 60% and 45% in arteries stored for 24 and 48 h in Krebs solution and by 34% and 86% in those stored in Eurocollins solution. In contrast, cold storage in the different media did not alter the relaxations elicited by sodium nitroprusside and forskolin. The endothelium-dependent relaxations in response to acetylcholine were not statistically modified after preservation up to 48 h in Hepes-Krebs solution. In contrast, the maximal relaxations to acetylcholine were significantly decreased after storage for 24 and 48 h in Belzer, Krebs and Eurocollins solutions. These results suggest that among the four media studied, Hepes-Krebs solution is the most suitable medium for the storage of blood vessels under hypothermic conditions.