[Effect of soft tissue crush injury on tensions of thoracic aortic rings in rats].

ABSTRACT

OBJECTIVE: To observe the effect of soft tissue crush injury on the tensions of thoracic aortic rings (TARs) in rats and to investigate the potential roles of nitric oxide in the change of the tensions. METHODS: Thirty adult SD rats were randomly divided into control group and crush injury (8 h and 16 h after injury) groups. Two kinds of TARs (one with endothelium and the other without endothelium) in vitro were prepared. In the TARs with endothelium, the tensions induced by phenylephrine (PE), acetylcholine (Ach), calcium ionophore A23187 and angiotensin II (AngI) were measured by the vascular tension detective technique. Then the TARs with endothelium were preincubated with nitric oxide synthase inhibitor N-nitro-L-arginine (L-NNA) for 20 minutes, the tensions induced by PE and Ang II were measured again. In the TARs without endothelium, the tensions induced by PE and Ang II were measured by the same method. RESULTS: In the TARs with endothelium, the tension of relaxation induced by cumulative doses of Ach and A23187 decreased significantly in 8 h and 16h groups. The tension of contraction induced by cumulative doses of PE and Ang II also decreased significantly (P<0.05). The tension of contraction increased after the preincubation with L-NNA. In the TARs without endothelium, the tension of contraction induced by PE and Ang II increased comparing to that of TARs with endothelium. CONCLUSION: The soft tissue crush injury can influence the tensions of TARs in rats and the vascular-derived NO can mediate the effects.