Effects of cold stress on expression of Hsp70 gene in blood lymphocyte of piglets

To explore effects of intensity and time of cold stress on expression of Hsp70 gene in blood Lymphocyte of piglets, Western-blotting and real-time PCR were performed to detect expression level of HSP70 gene, respectively. The results showed as followed: at -10 to -4 degrees C, HSP70 expression increased significantly for 0.5 h and subsequently decreased slightly before increasing markedly again at both 6 and 24 h; HSP70 mRNA expression level increased sharply after piglets were exposed for 0.5 h. The condition maintained for 6 h then declined at 12 h it reached a level apparently higher than the level prior to cold exposure at 24 h the transcription level recovered to normal. At -3 to 3 degrees C the expression level increased at 6 h but then returned to pre-exposure levels; mRNA increased significantly at 12 h. At 4-10 degrees C, no marked difference in expression level was detected. In conclusion, HSP70 mRNA expression showed the faster regular pattern therefore, it can be used as an objective parameter to evaluate animal cold stress conditions.