免疫应激对断奶仔猪免疫和神经内分泌激素的影响

试验研究了免疫应激对断奶仔猪免疫和神经内分泌激素的影响。选用 6头体重为 (7.6± 0 .3)kg的(2 8± 3)d的达兰断奶仔猪 ,绝食 12h后 ,随机选取 4头猪从腹膜注射 2 0 0 μg/kg(BW)的脂多糖 (LPS) ,另 2头注射等量生理盐水作对照。于注射后 0、1、2和 3h ,分别采血测定血浆白细胞介素 1β(IL 1β)、前列腺素E2 (PGE2 )、皮质醇、生长激素 (GH)和类胰岛素生长因子 I(IGF I)的含量。结果表明 :(1)注射LPS激活了应激轴 :与对照组相比 ,LPS提高了注射后 1h(P <0 .10 )、2h(P <0 .0 1)和 3h(P <0 .0 1)的IL 1β水平 ,提高了注射后 1h(P <0 .0 5 )和 3h(P <0 .0 1)的皮质醇和PGE2 水平 ;(2 )注射LPS抑制了生长轴 :LPS降低了注射后 3h的GH水平 (P <0 .10 ) ,降低了注射后 2h (P <0 .0 5 )和 3h(P <0 .0 1)的IGF I水平。结果显示 ,免疫应激激活了仔猪应激轴 ,而抑制了生长轴 ,在一定程度上揭示了免疫应激抑制生长的机制

Effects of Immunological Stress on Immune Parameter and Endocrine Hormones in Weanling Pigs

Six crossbred pigs (7.6±0.3)kg BW weaned at (28±3)d of age were used to investigate the effects of an immunological stress on pig immune parameter and endocrine hormones. At 12 h after starving, four pigs were selected randomly and injected intraperitoneally with 200 μg/kg BW of E.coli lipopolysaccharide (LPS), and two pigs were injected with an equivalent amount of sterile saline. Plasma samples were collected at 0, 1, 2 and 3 h postinjection for analysis of interleukin-1β(IL-1β), prostaglandin E_2(PGE_2), cortisol, growth hormone (GH) and insulin-like growth factor I (IGF-I). The results indicated: (1) LPS challenge increased IL-1β levels at 1 h (P<0.10), 2 h (P<0.01) and 3 h (P<0.01) postinjection and cortisol and PGE_2 at 1 h (P<0.05) and 3 h (P<0.01) postinjection; (2) LPS challenge decreased GH at 3 h (P<0.1) postinjection and IGF-I at 2 h (P<0.05) and 3 h (P<0.01) postinjection. These results suggest that an immunological stress activates stress axis and depresses growth axis, which elucidates the mechanism of growth retardance in immunologically stressed pigs.