| Objective The purpose of the present study was to investigate the effects of lyciumbarbarum polysaccharides (LBP) on weight of stress organ and the concentration ofcorticotropin-releasing hormone (CRH), cortisol(COR), heat shock70protein (HSP70),epinephrine (EPI) in plasma, and neuropeptide Y (NPY) mRNA level in hypothalamus in Ratsexposed to heat.Methods40Male SD rats were randomly divided into control (CN), Fixed time heatexposure group (FT), Continued time heat exposure group (CT), Fixed time heat exposure+LBP (FL), Continued time heat exposure+LBP (CL) group. Rats were kept in normothermictemperature (24.0±1℃) in control group, while the rats were exposed to heat in32±1℃in heat exposure group. The spleen, liver, heart, thymus, hypothalamic and pituitary werepicked up and weighed accurately after14days heat exposure; The plasma level of CRH, Cor,HSP70, EPI and immunoglobulin G (IgG) were detected by enzyme linked immunosorbentassay (ELISA) and the expression of hypothalamus neuropeptide Y mRNA and pituitaryproopiomelanocortin (POMC) mRNA was determined by Real-Time Quantitative PCR.Results The weight difference of rats in heat exposure groups had no obvious changethan CN group (P＞0.05). Compare with the CN group, the relative weight of spleen in CTand CL group, and the relative weight of liver in all heat exposure groups were significantlyreduced (P＜0.05), but the relative weight of spleen in FT and CT group were no significantlyreduced (P＞0.05). The relative weight of hypothalamic in CN, FT and CL group wereremarkably higher than that in CT group (P＜0.05) and the relative weight of heart, thymus and pituitary were no significant difference between CN group and all heat exposure groups.Compared with CN group, the plasma level of CRH, Cor, HSP70and EPI was increasedsignificantly in all heat exposure groups (P＜0.05), and the plasma level of HSP70in FL andCL group were significantly higher than FT and CT group (P＜0.05). The plasma level of IgGwas no significant difference between CN group and all heat exposure groups (P＞0.05). InFT group, the expression of NPY mRNA was significantly higher than CT and FL group (P＜0.05). Compared with CN group, the expression of NPY mRNA was markedly downregulatedin CT group (P＜0.05), and the expression of NPY mRNA in CL group was enormouslyup-regulated than CT group (P＜0.05). In FT group, the expression of POMC mRNA wasslightly higher than CT and FL group (P＞0.05). Compared with CN group, the expression ofPOMC mRNA was slightly down-regulated in CT group (P＞0.05), and the expression ofPOMC mRNA in CL group was up-regulated little than CT group (P＞0.05).Conclusion These results indicate that high-temperature environments could hurt thebody, and LBP have a potential protective function to the body by increasing the expression ofHSP70in plasma and NPY mRNA in hypothalamus. |
PDF Full Text Request