Abstract:

Aim: This study aimed to investigate whether endothelium-dependent and -independent relaxation responses can be preserved intact in the rat thoracic aorta after storage for 3, 6, and 18 hours in Krebs-Henseleit solution at +4 °C. Methods: Isolated organ bath model and 10-12 weeks old male Wistar rats were used to perform the experiments. To investigate the effect of endothelium-dependent relaxation factors, the cyclooxygenase inhibitor INDO was added to the Krebs-Henseleit solution to inhibit endogenous prostanoid synthesis. Submaximal contraction response was obtained with a single dose of PE and then ACh was administered cumulatively (10-9-10-4 M) to induce endothelium-dependent relaxation responses. Besides, smooth muscle-dependent relaxation responses were obtained by applying SNP cumulatively (10-9-10-5 M) following precontraction induced by PE. The statistical significance level was considered as p<0.05. Results: Thoracic aorta segments (0 hours, control) exhibited a mean contraction response of 3123 mg against 10-5 M PE. Although the responses slightly reduced in vascular rings stored for 3, 6, and 18 hours, no significant difference was observed (p>0.05). Besides, cumulatively administered ACh did not cause a significant change in endothelium-dependent relaxation responses (p>0.05). Similarly, SNP did not modulate the endothelium-independent relaxation responses in aortic segments after storage for 3, 6, or 18 hours (p>0.05). Conclusion: In the present study, the first physiological findings have been obtained that the endothelium-dependent and -independent contraction-relaxation responses of rat thoracic aortas can be preserved intact after storage periods of 3, 6, or 18 hours in Krebs-Henseleit solution at +4°C.

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