The anti-inflammatory effect of irisin on hyperbilirubinemia in neonatal rats
Objective:To investigate the effect of irisin on inflammatory response in brain tissue of neonatal rats with hy-perbilirubinemia.Method:Sixty-six neonatal SD rats were randomly divided into the normal control group(group A)and the model group(group M).Hyperbilirubinemia models were established by intraperitoneal injection of bilirubin so-lution at the age of 7 days and 10 days.After the last injection,6 rats were randomly selected from group A and M to verify the success of the model establishment,and then group M was randomly divided into group B and group C.Rats in group C were injected with 80 μg/kg irisin solution in lateral ventricles,and the oth-er groups were injected with the same amount of PBS.After the injection into lateral ventricle,groups A,B and C were further divided into three subgroups according to different points of death.Neurobehavioral tests were performed at each time point.Morphology of cortical or hippocampal nerve cells was detected by HE staining,and the concentrations of TNF-α,IL-1β and IL-6 were detected by ELISA.Result:At 12h,there was no significant difference in the time of plane righting reflex among the three groups(P>0.05);At 24h,the rats in group B and C were longer than those in group A(P>0.05);At 48h,group B was longer than group A and C(P<0.05),and there was no significant difference between group A and C(P>0.05).There was no significant difference in tropism test among the three groups at each time point(P>0.05).Under the HE staining,the cortex neuron structure in group A were clear and complete but the number of hippocampal neurons was reduce;in group B and C,the number of neurons in cortex and hip-pocampus was decreased,the structure was disordered,and different degrees of pathological damage were ob-served.Group C was better than group B.Under the ELISA,the concentrations of TNF-α,IL-1β and IL-6 in group B were higher than those in group A at each time point(P>0.05);the concentrations of TNF-α,IL1βand IL-6 in group C were significantly lower than those in group B at each time point(P>0.05);the concen-tration of TNF-α in the brain tissue of group C was higher than that of group A at 12h(P>0.05),and at 24h and 48h were lower than those in group A(P>0.05);the concentration of IL-6 in the brain tissue of group C was lower than that of group A at 12h and 24h(P>0.05);at 48h,there was no significant difference in the concentration of IL-6 between group C and group A(P>0.05);the concentration of IL-1β in the brain tissue of group C was not significantly different from that of group A at the three time points(P>0.05).Conclusion:Irisin can effectively reduce the release of TNF-α,IL-1β and IL-6 in the brain tissue of neonatal rats with hyperbilirubinemia,and play an anti-inflammatory role.