外源性脂多糖对山麻鸭雏鸭生长、血清激素、肝、脾及肌纤维发育的影响

Effect of exogenous LPS on growth,serum hormone,liver,spleen and myofiber development of Shanma duckling

旨在探究不同浓度外源性细菌脂多糖(LPS)对山麻鸭雏鸭生长、血清激素、肝、脾及肌纤维发育的影响,选择24只体重相近的7日龄健康雌性山麻鸭,每隔2 d进行腹腔皮下注射(0.5 mL),随机平均分为4组,高浓度LPS组(500μg/kg LPS)、高浓度对照组(聚乙烯吡咯烷酮缓释剂)、低浓度LPS组(200μg/kg LPS)、低浓度对照组(生理盐水),每天记录采食量,每隔2 d称重,22日龄时对山麻鸭血液进行生长激素(GH)、白介素-6(IL-6)和内毒素检测,对肝脏、脾脏及腿肌组织进行HE染色,对肌细胞生成素(Myog)和肌球蛋白重链1(Myh1)基因进行实时荧光定量PCR检测。结果显示:低浓度LPS组和低浓度对照组体重差异不大(P>0.05);高浓度LPS组体重从11日龄开始显著低于高浓度对照组(P<0.05);低浓度LPS组中,肝脏、脾脏基本组织结构完整,伴有数量不等的空泡样变,出现轻微的病理变化,高浓度LPS组空泡样变更为明显;高浓度LPS组山麻鸭腿肌肌纤维直径极显著低于高浓度对照组(P<0.01),肌纤维密度没有显著差异(P>0.05),Myh1基因表达显著降低(P<0.05);低浓度LPS组肌纤维直径、密度以及Myog和Myh1基因的表达和低浓度对照组比均无显著差异(P>0.05)。结果表明:低浓度外源性LPS对麻鸭的采食量、体重、腿肌、肝脏和脾脏影响程度较小,而高浓度外源性LPS会导致鸭的采食量下降,体重显著降低,血液中GH和IL-6下降,对肝脏和脾脏组织有一定的损伤,并显著抑制了肌纤维的发育。

This study was designed to investigate the effects of different concentrations of exogenous lipopolysaccharide(LPS)on growth,serum hormone,liver,spleen and myofiber development of Shanma ducklings.Twenty-four 7-day-old female Shanma ducklings with similar body weight were equally divided into a high-concentration LPS group(injected with 500μg/kg LPS every two days),a high-concentration control group(injected with PVP sustained-release agent every two days),a low-concentration control group(injected with saline every day)and a low-concentration LPS group(injected with 200μg/kg LPS every day).Feed intake was recorded daily and the ducks were weighed every 2 days.At the age of 22 days,the blood samples of the ducklings were tested for GH,LPS and IL-6 concentration,while their leg muscle,liver and spleen were sampled for HE staining.It was found that there was no significant difference in the body weight between the control group and the low-concentration LPS group(P>0.05).From the 11 days of age,the weight of the high-concentration LPS group was significantly lower than that of the control group(P<0.05).In the low-concentration LPS group,the basic structures of the liver and spleen were intact,accompanied by different amounts of vacuolus,showing slight pathological changes;while in the high-concentration LPS group,the vacuolus was more obvious.The myofiber diameter and Myh1 expression in the high-concentration LPS group were significantly lower than those of the control group(P<0.05),but the myofiber density showed no significant difference(P>0.05)between the groups.The expression of Myog/Myh1 and the myofiber diameter/density showed no significant difference in the low-concentration LPS group(P>0.05).The above results indicated that low concentration of exogenous LPS had little influence on feed intake,body weight,leg muscle/liver/spleen development of Shanma ducklings,while high concentration of exogenous LPS decreased feed intake,body weight,and blood GH/IL6 concentration of Shanma ducklings,and also caused certain damage to their liver/spleen tissues and inhibited myofiber hypertrophy in the birds.