表皮生长因子对肉鸡十二指肠形态结构、消化酶活性以及表皮生长因子受体表达的影响

Effects of Epidermal Growth Factor on Duodenal Morphology,Digestive Enzyme Activities and Epidermal Growth Factor Receptor Expression of Broilers

本试验旨在研究肉鸡饲粮中添加表皮生长因子(EGF)对十二指肠形态结构、消化酶活性和表皮生长因子受体(EGFR)表达的影响。试验选用72只1日龄爱拔益加(AA)肉鸡,随机分成4个组,每组3个重复,每个重复6只。对照组(CK组)饲喂基础饲粮,抗生素组(K组)在基础饲粮中添加250 mg/kg盐酸金霉素,EGF组(E组)在基础饲粮中添加500 mg/kg EGF,EGF+抗生素组(E+K组)在基础饲粮中添加500 mg/kg EGF+250 mg/kg盐酸金霉素。试验期为42 d。采用苏木精-伊红(HE)染色、双抗体夹心和原位杂交方法,分别检测了十二指肠黏膜形态,碱性蛋白酶、脂肪酶和α-淀粉酶活性以及EGFR的表达。结果表明:1)28、35、42日龄时,各组十二指肠碱性蛋白酶活性无显著差异(P>0.05),但E组十二指肠碱性蛋白酶活性均为最高。21、28、35、42日龄时,各组十二指肠脂肪酶活性无显著差异(P>0.05),但E组十二指肠脂肪酶活性均为最高。35日龄时,E组十二指肠α-淀粉酶活性显著高于CK组和E+K组(P<0.05);42日龄时,E组十二指肠α-淀粉酶活性极显著高于K组和E+K组(P<0.01)。2)21日龄时,E组十二指肠EGFR基因平均光密度值显著高于CK组(P<0.05);42日龄时,E组和K组十二指肠EGFR基因平均光密度值极显著高于CK组和E+K组(P<0.01)。3)21日龄时,K组和E组十二指肠绒毛高度和绒毛高度/隐窝深度显著高于CK组(P<0.05)。28、35和42日龄时,各组十二指肠绒毛高度、隐窝深度和绒毛高度/隐窝深度无显著差异(P>0.05)。21、35和42日龄时,E组绒毛高度/隐窝深度均为最高。综上所述,饲粮添加500 mg/kg EGF能促进21、28、35、42日龄肉鸡十二指肠黏膜形态的发育,增强十二指肠中碱性蛋白酶、脂肪酶和α-淀粉酶活性,提高十二指肠EGFR的表达。

The purpose of this experiment was to study the effects of dietary epidermal growth factor(EGF)on duodenal morphology,digestive enzyme activities and epidermal growth factor receptor(EGFR)expression of broilers.Seventy-two 1-day-old Arbor Acres(AA)broilers were randomly divided into 4 groups with 3 replicates per group and 6 chickens per replicate.The control group(group CK)was fed a basal diet,the antibiotic group(group K)was fed the basal diet supplemented with 250 mg/kg chlortetracycline hydrochloride,the EGF group(group E)was fed the basal diet supplemented with 500 mg/kg EGF,and the EGF+antibiotic group(group E+K)was fed the basal diet supplemented with 500 mg/kg EGF+250 mg/kg chlortetracycline hydrochloride.The test period was 42 days.The hematoxylin-eosin(HE)staining,double antibody sandwich and in situ hybridization methods were used to detect the duodenal mucosa morphology,the activities of alkaline protease,lipase andα-amylase and the expression of EGFR.The results showed as follows:1)at 28,35 and 42 days of age,there was no significant difference in duodenal alkaline protease activity among all group(P>0.05),but the duodenal alkaline protease activity in group E was the highest.At 21,28,35 and 42 days of age,there was no significant difference in duodenal lipase activity among all group(P>0.05),but the duodenal lipase activity in group E was the highest.At 35 days of age,the duodenalα-amylase activity in group E was significantly higher than that in group CK and group E+K(P<0.05);at 42 days of age,the duodenalα-amylase activity in group E was significantly higher than that in group K and group E+K(P<0.01).2)At 21 days of age,the duodenal EGFR gene average optical density in group E was significantly higher than that of group CK(P<0.05);at 42 days of age,the duodenal EGFR gene average optical density in group E and group K was significantly higher than that in group CK and group E+K(P<0.01).3)At 21 days of age,the duodenal villi height and villus height/crypt depth in group K and group E were significantly higher than those in group CK(P<0.05).At 28,35 and 42 days of age,there were no significant differences in the duodenal villi height,crypt depth,and villus height/crypt depth among all groups(P>0.05).At 21,35 and 42 days of age,the villus height/crypt depth in group E was the highest.In summary,diet adding 500 mg/kg EGF can promote the development of the duodenal mucosa morphology of broilers at 21,28,35 and 42 days of age,and enhance the activities of alkaline protease,lipase andα-starch in duodenum,improve the duodenal EGFR expression.