Effects of inducible hypothermia on expressions of PGC-1 and SHP in rat model of hemorrhagic shock / 中华急诊医学杂志

ABSTRACT

Objective To investigate the effects of inducible hypothermia on expressions of peroxisome proliferator activated receptor gamma coactivator-1 (PGC-1) and small heterodimer partner (SHP) in rat model of hemorrhagic shock.Methods SD rats were randomly (random number) divided into three groupscontrol (C),normothermia (N) and hypothermia (H).Exsanguination was carried out in rats by continuously drawing out venous blood (25 mL/kg) over 15 minutes to establish hemorrhagic shock model.Then,rectal temperatures of rats were maintained by body surface cooling to 32℃ in H group and by body surface warming to 38℃ in N group,respectively.After a shock period of 60 minutes,rats received the infusion of whole blood of their own and lactated Ringer's solution (1 ∶ 2) treatment for 60 min.Rats were warmed to 38℃ by body surface warming and monitored for 3 h after resuscitation.Hematocrit (Hct),base excess (BE),lactate (Lac),and glucose (Glu) were recorded before modeling and after different lengths of hemorrhagic shock period (HSP).The expressions of PGC-1 mRNA and SHP mRNA and the levels of their protein in liver were tested by real-time reverse transcription polymerase chain reaction (qRT-PCR) and western blotting,respectively.Results The H group had lower lactate levels and higher BElevels than the N group [(6.3±2.1) vs.(10.4±1.5) and (-4.7±2.5) vs.(-9.0±3.2)] (P＜ 0.05).At 72 hours after modeling,there were four survivors in the N group and seven survivors in the H group (P ＜ 0.05,Log Rank).The expressions of PGC-1 mRNA and SHP mRNA increased in N group.Hypothermia resuscitation down-regulated PGC-1 mRNA expression,meanwhile,increased expression of SHP mRNA.Both Hypothermia and Normothermia resuscitation increased SHP protein levels,but decreased PGC-1 protein levels.Conclusions Inducible hypothermia ameliorated acidosis and energy metabolism imbalance through adaptive regulation in PGC-1 and SHP.