Dynamic changes of epidermal growth factor and its receptor in neonatal rats with intestine injury / 中华围产医学杂志

ABSTRACT

Objective To determine the dynamic changes of ileum epidermal growth factor(EGF),transforming growth factor-α(TGF-α)and epithelial growth factor receptor(EGFR)in neonatal rats with intestinal injury and to investigate their role in the neonatal necrotizing enterocolitis(NEC). Methods One-day-old Wistar rat pups were divided into two groups.The rats in the lipopolysaccharide(LPS)-injected group(n=40)received an intraperitoneal injection with 5 mg/kg LPS and those in the control group(n=8)did not.Control group and LPS-injected group at 1,3,6,12 and 24 h following LPS challenge were sacrificed for histological evaluation of NEC and for measurernents of EGF,EGFR,EGFR mRNA and TGF-α mRNA. Results Compared with the control group(0.12 0.17).the LPS-iniected pups showed a significant increase in injury scores at 1,3,6,12 and 24 h(1.28±0.62,1.75±0.74,1.98±0.75,2.85±0.41 and 2.35士0.63,respectively)(P<0.01).EGF protein levels at 1,3,6,12,24 h[(235.9±44.3)pg/mg prot,(231.8±30.0)pg/mg prot,(223.3±48.1)pg/mg prot,(211.7±47.0)pg/mg prot and(221.4±39.0)pg/mgprot,respectively]were significantly lower than that of the control group[(287.7±42.6)pg/mg prot](P<0.05).There was a negative correlation between the EGF levels and the grade of intestinal injury within 24 h(r=1.000,P<0.01).The expression of EGFR protein and mRNA was increased after LPS administration.There was no correlation between the EGFR protein and the grade of intestinal injury(r=0.800,P>0.05).The expression of TGF-α mRNA was significantly up-regulated at 1 and 3 h following LPS injection. Conclusions Reduced levels of EGF may play a pivotal role in the pathogenesis of NEC.