Effect of glutamine on the expression of Caspase 3 and proliferating cell nuclear antigen in the intestinal tissue of neonatal rats with necrotizing enterocolitis / 中国新生儿科杂志

ABSTRACT

Objective To study the expressions of cysteinyl aspartate specific proteinase 3 ( Caspase 3 ) and proliferating cell nuclear antigen ( PCNA ) in intestinal tissue of neonatal rats with necrotizing enterocolitis ( NEC ) , and the protective effect of glutamine ( Gln ) on NEC. MethodsThirty-six neonatal Sprague-Dawley ( SD) rats were randomly assigned into 3 groups at 48 h after birth (12 in each group). The control group were fed with milk replacer. The NEC group were fed with milk replacer and experiencing cold exposure after hypoxic-reoxygenation twice a day for 3 days, The Gln+NEC group were fed with milk replacer plus Gln and experiencing cold exposure after hypoxic-reoxygenation twice a day for 3 days. All the rats were sacrificed and intestinal tissues obtained at day 3 of the establishment of model. The histological changes of ileal tissues were studied using hematoxy lin-eosin ( HE ) staining. The expressions of Caspase 3 and PCNA were detected using immunohistochemical(IHC)method.Results Caspase3expressioninNECgroup(77.3±8.6)℅was significantly higher than the control group (18. 9 ± 3. 4)℅ and Gln+NEC group (50. 3 ± 6. 2)℅ ( P<0. 05). Also, Caspase 3 in Gln+NEC group was significantly higher than the control group (P<0. 05). PCNA expression in the NEC group ( 15. 0 ± 1. 9 )℅ was significantly lower than the control group (34. 2 ± 5. 8)℅ and the Gln +NEC group ( 24. 0 ± 3. 9 )℅ ( P <0. 05 ) . PCNA expression in the Gln+NEC group was significantly lower than the control group ( P<0. 05). The pathological score of the intestinal tissues was significantly correlated with Caspase 3 expression ( r = 0. 769, P = 0. 005 ), Caspase3/PCNA ratio (r=0. 835,P=0. 002) and PCNA expression (r= -0. 698, P=0. 014) in the NECgroup.Conclusions Up regulation of Cas pase3 and down regulation of PCNA might be correlated with the process of NEC. Gln might be effective in prevention and healing of NEC by inhibiting apoptosis and promoting cell proliferation.