| Northeast forest frog (Rana dybowskii) takes an important economic place, and it is one of the most important medical animals in Heilongjiang Province. Heilongjiang province is placed in the mid-high degree of latitude. Northeast forest frog hibernates here will face threaten of low temperature, and its cold-tolerant mechanism is rigorously controlled by the economy. By now, there is seldom report on the northeast forest frog which hibernates at low temperature condition. Our study mainly concern on the change of inner sugar, fat and protein at low temperature, and finding out the relationship between the change rule of inner substance and cold tolerance. Its cold-tolerant mechanism has an important applied value, and a great potential for exploitation and utilization.We choosed the northern forest frog which from Yichun, Heilongjiang province. Using the method of dropping temperature gradually , extending time, drying, Suo elicit, Kai nitrogen determination, o-Toluidine method, and Ant hrone2Sulp huric acid colorimeter to test the northeast forest frog's survive ratio, water content, dissociated fat content, protein content, blood glucose level, and glucide content in low tempreture(4℃~-3℃). We also tested the blood glucose level, glucide content and muscle glucose content change rule of the frog which accepted different concentration glucose at 4℃ and -2℃. By using the organizational slice technique, we observed different glucose and low temperature effected liver organism and muscle tiny Structures by compare with the group which injected 115mM PBS.The result: the northeast forest frog's survive ratio is 100% at 4℃ , 0℃, -1 ℃ after low temperature intimidate, survive ratio fell to 0 at -2℃ and 0 at -3℃. When it descended from 4 ℃ to -3℃, the inner total water content reduced gradually, while the combined water raised. Between northeast forest frog heat and water content had linearity relationship While unsaturated fatty acid content was almost unchanged in our experiment. It had significant difference between contrast and test protein content (P〈0.01), and when it descended from 4℃ to -2℃, its inner protein unchanged. From 4℃ to -3℃, blood glucose level increased from (184.97+13.18) mg/100ml to (305.26 + 5.88) mg/100ml, increased distinctly with contrast (PO.01). From 4℃ to -3℃, liver glycogen content decreased from(4.68 + 0.08)% to(3.10± 0.0)%, decreased distinctly with contrast (P<0.01). Northeast forest frog accepted glucose concentration had significant positive relation with blood glucose level, liver glycogen content and muscle glucose content, while the liver glycogen content reached the pinnacle when it accepted 1500mM glucose PBS. Compare with the -2℃ group and 4℃ group, liver glycogen content decreased, blood glucose level and muscle glucose content increased. Under interfere of the exterior glucose;it did not change obviously in liver and skeletal muscle structures in thetwo groups. But following with the increase of the concentrate of glucose, the liver sinusoidal between liver cable increased, in 1500mM PBS the liver sinusoidal interspace was the biggest, following the increase of concentration of PBS decreased.Results indicated: Northeast forest frog's critical temperature was -1 °C, but could not live in -2°C and -3°C for a long time. Rough fat had no significant change because metabolize level was low. Protein might be not the mainly means in adjusting low temperature hibernation. In low temperature, the glucose increased while the liver glycogen decreased, combine water increased while dissociated water decreased. These indicated that northeast forest frog's cryoprotectant was glucose which come from liver glycogen decomposing. There will be low organ dehydration during the raise of the blood sugar and decrease of the liver glycogen. It will enhance the ability of endure low temperature. The glycide of northeast forest frog changed dynamicly, but it had little effect on tissue structures.
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