Abstract: Objective To observe the effect of cyclosporin A (CsA) on the vasoconstriction/vasodilation of the superior mesenteric artery (SMA), vital organ and mitochondrial function after traumatic hemorrhagic shock in rats. Methods With the traumatic hemorrhagic shock model of rats (blood pressure maintained at 40 mmHg and femur was fractured), rats were divided into six groups: sham-operated, shock, LR, CsA 1, 5, 10 mg/kg (n=8/group). After shock, rats received an infusion of LR or CsA, then the vascular constriction/relaxation of SMA was observe with isolated organ perfusion system, the blood flow in liver and kidney was measured by a laser doppler blood flowmeter, the function of the liver and kidney was measured using biochemical analysis, and the mitochondrial function of the liver, kidney and small intestine was examined by the respiration control rate method. Results After shock, both the vascular constriction reactivity and the vasodilator reactivity were significantly decreased. CsA markedly restored the decreased constriction and relaxation of SMA after shock (P<0.01~0.05), and 5 mg/kg of CsA showed a better effect. CsA (5 mg/kg) also improved tissue blood flow, organ and mitochondrial function in shock rats (P<0.01~0.05). Conclusions CsA has good effects on traumatic hemorrhagic shock through improving vascular function, increasing tissue blood flow, protecting organ and mitochondrial function.

Key words: cyclosporin A, trauma, hemorrhagic shock, organ function