Analysis On The Changes On The Liver Proteins, SOD, LDH, G6PDH And EST Activities Of Heilongjiang Wood Frog Under Low Temperature

The Heilongjiang wood frog (Rana amurensis Boulenger) mainly distributes in northeastforest region of our country. This region is placed in the mid-high degree of latitude and it isexposed to temperatures below 0℃throughout the winter. So the Heilongjiang wood froghibernates here will face threaten of low temperature, and its cold-tolerant mechanism isrigorously controlled by the economy. By now, there is seldom report on the Heilongjiangwood frog which hibernates at low temperature condition. Our study mainly analyze theadaptation changes of liver proteins, SOD, LDH, G6PDH and EST activities of Heilongjiangwood frog under low temperature. It is significance to further study the tolerance mechanism ofHeilongjiang wood frog during hibernation. Its cold-tolerant mechanism has an importantapplied value and a great potential for exploitation and utilization.We choosed Heilongjiang wood frogs from Yichun, Heilongjiang province. The frogssurvival ratios at room temperature, 1℃Cand -2℃were observed. The method of 2-D native-PAGE/SDS-PAGE, colorimetry examining enzyme activity and isoenzyme PAGE were used toanalyze the adaptation changes of the frog's liver proteins, SOD, LDH, G6PDH and ESTactivities.The result: the Heilongjiang wood frog's survival ratios were 100ï¼…at 14℃and 1℃after 72h low temperature stress and survival ratio fell to 84.6ï¼…after 24h exposed at -2℃.The SOD and the LDH-1 activities and EST (R_f=0.17 and R_f=0.72) at 1℃weresignificantly higher than the values of the room temperature(P＜0.05), but the total enzymeactivities of LDH, G6PDH and EST at room temperature and 1℃were similar(P＞0.05).This showed well-developed anoxia tolerance of the Heilongjiang wood frog to maintainplasma viability when low temperature interrupts the delivery of oxygen and substrates. LDH-1rose significantly avoided the liver lactic acid accumulation that may created the liver to bewearied. EST (R_f=0.17 and R_f=0.72) rose may enhance the ester metabolism to offer muchenergy. These showed steady metabolic rate and relative stable organism environment of theHeilongjiang wood frog to survive under low temperature.Native PAGE separated proteins of liver tissue successfully on the better condition is 6ï¼…final gel concentration and there were 15～19 bands identified on this condition. The content ofone liver protein band (R_f=0.79) at 1℃was significantly higher than at room temperature (P＜0.05).On the 2-D native-PAGE/SDS-PAGE gel, the content of P spot (MW=51kDa, R₁=0.47on the 1D native PAGE gel) at 1℃was significantly higher than at room temperature (P＜0.05), and the content of N spot (MW=65 kDa, R_f=0,94 on the 1D native PAGE gel) at roomtemperature was significantly higher than at 1℃. These protein spots may be related with the adaptation to the low temperature of the Heilongjiang wood frog.