Effect of dopamine on diaphragmatic fatigue in vitro induced by hypoxic hypercapnic acidosis in rats

Objective: To observe the treatment effect of dopamine on diaphragmatic fatigue in vitro induced by hypoxic hypercapnic acidosis in rats.Methods: Thirty-two SD rats were divided into four groups at random:control group,control group with dopamine,model group,model group with dopamine.Control group and control group with dopamine were aerated oxygen(95%O₂+5%CO₂),model group and model group with dopamine were aerated hypoxic hypercapnic acidosis gas(21%O₂,12%CO₂,67%N₂) for 4 min.At the same time dopamine (1 mmol/L) was added to the second and forth groups.Data(Pt,Po,CT,1/2RT) was recorded and analyzed using the Medlab-U/4c biological signal collecting system.Results: Compared with control group,the Pt,Po and contractile force under different frequency of model group decreased significantly(P<0.05 and P<0.01);but the Po and contractile force under the frequencies 30-100 Hz of dopamine increased significantly(P<0.05) compared with those of model group.Conclusions: Dopamine can improve contractility and treatment of high frequency fatigue induced by hypoxic hypercapnic acidosis to some extent.