Effects of nitric oxide synthases inhibitor on severe hemorrhagic shock / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effects of aminoguandine(AG) used as a selective inhibitor of the inducible isoform of nitric oxide synthase(iNOS) and L NAME used as a non selective inhibitor of nitric oxide synthase(NOS) on severe hemorrhagic shock Methods Forty rabbits were bled to mean arterial pressure of 4 4 66 kPa via femoral artery Hypotention was maintained for 120 min, the shed blood was then returned, followed by an infusion with Ringer′s solutions Animals were randomly divided into three groups hemorrhagic shock group (n=14), AG group (AG 20mg/kg was infused intravenously ,n=14), L NAME group (L NAME 30mg/kg was infused intravenously with ,n=12) Plasma levels of endotoxin, tumor necrosis factor(TNF?) and nitric oxide (NO) were determined before and after shock, immediately after resuscitation and 0 5h, 2h, 4h after resuscitation The 24h and 48h survival rates were recorded Lung, intestine, liver and kidney tissues were obtained 48 h after shock for microscopic examination Results The plasma endotoxin, TNF? and NO levels markedly increased and were kept at high levels after shock Lower plasma levels of endotoxin TNF? and NO, less tissue damages and high survival rates were observed in AG group as compared with those in L NAME group and shock group Conclusions The endotoxin,TNF? and NO play an important role in the development of irreversible shock AG is beneficial in the treatment of hemorrhagic shock, while L NAME does not improve the outcome of shock