脂多糖刺激对断奶仔猪下丘脑-垂体-肾上腺轴PPARγ表达的影响

Effects of Lipopolysaccharide Challenge on PPARγ Expression in Hypothalamus Pituitary Gland Adrenal Gland Axis of Weanling Pigs

研究脂多糖(LPS)对断奶仔猪下丘脑-垂体-肾上腺(HPA)轴过氧化物酶体增殖物活化受体γ(PPARγ)表达的影响。对照组注射生理盐水,试验组注射LPS。注射后1.5 h和3 h采血,3 h采血后屠宰。结果表明:LPS刺激后1.5 h,中性粒细胞含量及其比例显著下降(P<0.05);LPS刺激后3 h,白细胞、淋巴细胞、中性粒细胞含量显著下降(P<0.05)。LPS刺激后1.5 h,血浆肿瘤坏死因子(TNF)-α、皮质醇和促肾上腺皮质激素释放素激素(CRH)含量显著上升(P<0.05);LPS刺激后3 h,血浆TNF-α、皮质醇和促肾上腺皮质激素(ACTH)含量显著上升(P<0.05);LPS刺激导致下丘脑、腺垂体、肾上腺皮质和髓质中PPARγ阳性细胞百分率显著升高(P<0.05)。这表明LPS导致免疫应激,激活HPA轴,诱导HPA轴PPARγ的表达。

The experiment was conducted to investigate the effects of lipopolysaccharide（LPS） on peroxisome proliferator-activated receptor-γ（PPARγ） expression in the hypothalamus pituitary gland adrenal gland（HPA） axis of weanling pigs.The pigs in the treatment group were injected intraperitoneally with LPS,whereas pigs in the control group were injected with sterile saline.Blood samples were collected at 1.5 and 3 h post-challenge.Following blood collection at 3 h,the pigs were slaughtered.The results showed that.at 1.5 h,LPS reduced neutrophil number and proportion（P〈0.05）.At 3 h,LPS reduced white blood cell,lymphocyte and neutrophil（P〈0.05）.Tumour necrosis factor-α and cortisol were increased significantly 1.5 and 3 h after LPS challenge（P〈0.01）,adrenal cortical hormone was increased significantly 1.5 h after LPS challenge（P〈0.05）,and adrenocorticotropic hormone was increased significantly（P〈0.05） 3 h after LPS challenge.LPS challenge increased PPARγ-positive cell percentage in the hypothalamus,adenohypophysis,adrenal cortex and adrenal medulla（P〈0.05）.These results indicate that LPS challenge induces acute immunological stress in Pigs,and actives HPA axis and induces PPARγ expression of HPA axis.