枸杞多糖对热暴露大鼠血浆中CRH、HSP70和脑垂体POMC基因表达水平的影响

Effects of LBP on the Plasma Level of CRH,HSP70 and POMC m RNA Expression in Pituitary in Heat Exposure Rats

通过对热暴露大鼠进行枸杞多糖干预,观察大鼠应激器官重量和血浆促肾上腺皮质激素释放激素(corticotropin releasing hormone,CRH)、热休克蛋白70(Heat shock 70 protein,HSP70)、免疫球蛋白G(immunoglobulin G,Ig G)及垂体阿黑皮素(proopiomelanocortin,POMC)m RNA表达水平的变化。与对照组(CN)相比,热暴露组(HE)和热暴露+枸杞多糖组(HL)大鼠脾脏、肝脏器官相对重量明显降低,血浆CRH、HSP70含量明显增高(P<0.05);HE组下丘脑器官相对重量明显降低(P<0.05);LBP明显增高大鼠下丘脑器官相对重量及血浆HSP70的表达水平(P<0.05);HE和HL组大鼠心脏、胸腺器官相对重量,血浆中Ig G含量及垂体POMC m RNA表达水平与对照组相比无明显改变(P>0.05)。结果表明,热暴露会对机体产生不利影响,枸杞多糖可通过增高HSP70的表达来对热暴露状态下的机体进行保护。

High temperature beyond the range of the thermal neutral zone has been regarded as the deadliest stimulation in rodents. It will touch off all sorts of biological response .,incur neurological, endocrine disorders and immune dysfunctions. In Chi- na,Lycium barbarum has been used for centuries to keep healthy, it has a high levels of polysaccharides. The objectives of this study were ： （ 1 ） to investigate the effects of heat exposure on weight of stress organ and the concentration of corticotropin releasing hormone （CRH） ,heat shock 70 protein （HSPT0） ,immunoglobulin G （IgG） in plasma and proopiomelanocortin （POMC） mRNA level in pituitary; （2） to investigate the alleviating effects of polysaccharides from Lycium barbarum （LBPs） interference under heat exposure on these physiological parameters in SD rats. Five - week - old SD male rats were randomly divided into control （CN） ,heat exposure（HE） and heat exposure ＋ LBP （HL） group. Rats were kept in a room with temperature （24 ± 1 ） ℃ ,rela- tive humidity of （60 ± 5 ） % in CN group,while the rats were exposed to （32 ± 1 ） ℃, relative humidity of （60 ± 5 ） % in HL and HE group. The spleen,liver, heart, thymus, hypothalamic and pituitary were picked up and weighed accurately after 14 days heat exposure;moreover, the plasma levels of CRH, HSP70 and IgG were detected by enzyme linked immunosorbent assay and mRNA expression of POMC was determined by Real - Time Quantitative PCR. Compared with CN group, the relative weight of spleen,liv- er and hypothalamic was significantly reduced, and the plasma levels of CRH and HSPT0 was increased significantly （ P 〈 0.05 ） in HE group. In contrast, rats in HL group ~ （ 1 ） remarkably decreased the relative weight of spleen and liver than CN group, sig- nificantly enhanced the relative weight of hypothalamic than CN and HE groups （ P 〈 0.05 ） ; （ 2 ） remarkably increased plasma levels of CRH than CN group （ P 〈 0.05 ） ; （3） enormously enhanced the expression of HSP70 than HE and CN groups （ P 〈 0. 05 ）. However, in HE and HL group, the relative weight of heart and thymus, the plasma levels of IgG and the expression of POMC mRNA had no obvious change than CN group （ P 〉 0.05 ）. These results indicate that heat exposure could have an adverse effect on the body, and LBP has a potential protective function to the body by increasing expression of HSPT0.