Effects of Inhalational Anesthetics on Contractile Responses and Nitric Oxide Synthase Activity in Endotoxemic Rats / 대한마취과학회지

ABSTRACT

BACKGROUND: Recent studies revealed that inhalational anesthetics (IA) attenuate NO production. But the hemodynamic changes produced by IA in septic syndrome patient are still sufficient to threaten patient, surgeon and anesthesiologist. So we examined which IA is proper to maintain vascular contractile force and evaluated the effects of NOS inhibitors on contractile force of septic rat aorta under IA. METHODS: Aortic ring preparation was obtained from LPS-treated (1.5 mg/kg, i.p. for 18h) rats. The development of sepsis was confirmed by iNOS activity and iNOS expression using RT-PCR. Contractile responses of aorta to phenylephrine admministation in the presence or absence of halothane, enflurane and isoflurane were evaluated. We also evaluated the effects of NOS inhibitors, one is NG-nitro-L-arginine methyl ester (L-NAME) and the other is aminoguanidine. Statistical significances (p<0.05) were analyzed according to data characteristics by unpaired t-test and paired t-test. RESULTS: The contractile responses to phenylephrine admministration were attenuated in LPS-treated rings. Isoflurane, even at the dose of 2 MAC, didn't affect the contractile response while both halothane and enflurane decreased the contractile response even at the dose of 1 MAC. The potentiation of contractile responses by NOS inhibitors were not affected during administeration of IA. CONCLUSIONS: From these results, it is suggested that isoflurane is the safest inhalational anesthetic and NOS inhibitors, especially L-NAME, may be very useful in the therapy of septic shock patients during general anesthesia.