Effects of hypertonic solution (NaCl 7,5%) on the inflammatory response in an experimental model of hemorrhagic shock

Abstract

Hypertonic saline solution (HSS - NaCl 7,5%) was shown to restore hemodynamic parameters in hemorrhagic shock and to decrease the inflammation triggered by ischemia reperfusion injury (I/R). Therefore, our objective was to investigate the effects of HSS on the mechanisms involved in I/R, in an experimental model of controled hemorrhagic shock. Wistar rats (280-350 g) were submitted to controled bleeding, keeping the mean arterial pressure around 40 mmHg, for 1 hour. After that, rats were randomized and treated with HSS (4 ml/kg)or normal saline (ISS) (34 ml/kg). There were no differences in hemodynamic parameters between the two groups for at least 2 h after shock. No difference either was observed in reactive oxygen species generation (measured indirectly by malondialdehyde concentration)or cytokines (IL-6 and IL-10) production (measured by ELISA). Qualitative analysis of lung tissue showed a smaller neutrophil infiltrate in animals that received HSS. Also, the animals in the HSS group showed an increased expression of heat shock protein 70 (HSP70). Therefore,we conclude that treatment of hemorrhagic shock with hypertonic saline solution can decrease pulmonary inflammation and increase cellular protection by up-regulating HSP70 expression.