New approach to treatment of shock--restitution of vasoreactivity

Our objective was to observe the therapeutic effect of restituting vasoreactivity agent in severe shock. A hemorrhagic shock (HS) model was reproduced in rat and the response of arterioles of spinotrapezius muscle to norepinephrine (NE) in HS was tested. The diameter, blood velocity, and volumetric flow in arteriole, and the mean arterial pressure (MAP) were measured. The therapeutic effect was observed after the treatment of restituting vasoreactivity agent (glybenclamide--an inhibitor of ATP sensitive potassium channel, and tiron--an oxygen free radical scavenger). The arteriolar vasoreactivity was significantly reduced with 15 fold increase of NE threshold 2 h post HS. After treated with restituting agent (RA), the vascular hyporeactivity of rat was apparently recovered, and the increased level of MAP following injection of dopamine was 1.8 times and 1.9 times more than that in NS-treated and DMSO-treated group respectively. After reinfusion of shed blood, the value of systemic blood pressure maintained more than 100 mmHg and volumetric flow in arterioles in RA group were 2 times more than those in NS treated group within the 2 h observation periods. The average survival time in RA treated group was also 1.8 times and 1.6 times longer than that in NS-treated and DMSO-treated group respectively. The restituting vasoreactivity agent is able to recover the lower vasoreactivity with excellent anti-shock effect in severe hemorrhagic shock.