THE ALTERATION AND SIGNIFICANCE OF NITRIC OXIDE SYNTHASE IN VITAL ORGANS DURING TRAUMATIC SHOCK / 解放军医学杂志

ABSTRACT

In order to investigate the dynamic changes in nitric oxide synthase (NOS) activity in organs during traumatic shock and to evaluate the effects of inhibitor of NOS and L Arginine (L Arg) on traumatic shock, rat model of traumatic shock was established, and the constitutive NOS and inducible NOS in the heart, small intestine, liver, lung , spleen were measured 0 5h, 3h, 5h after traumatic shock. Followed by intravenous injection with aminoguanidine (AG ), N G nitro L arginine methyl ester (L NAME), or L Arg, NOS were again measured, and the survival time and 24h survival rate were recorded. It was found that in normal rats cNOS was expressed in all organs, but only a weak iNOS expression in lung and liver. Half an hour after shock, cNOS was elevated in almost all organs in various degrees but there was no change in iNOS. 3h after shock, an increase in iNOS activity and a decrease in cNOS were observed. The iNOS was synthesized in large quantity 5h after shock. AG and L Arg markedly prolonged the survival time but L NAME did not in shock rats. AG inhibited the activity of iNOS but promoted the synthesis of cNOS, and both NOS were inhibited in L NAME group, but not in L Arg group. The results that iNOS was synthesized in large quantity only at later period of traumatic shock. To treat shock, the inhibitors of NOS and L Arg should be given according to the degree of shock, the dosage of drugs, and the time of administration