Effect Of Temperature On Liver Regeneration After 68% Hepatectomy In Normal Rats

Objective To investigate the effect of different body temperatures on liver regeneration after 68%hepatectomy in rats.Methods1.Pre-experiment: 6 clean-grade Wistar male rats were randomly selected for each temperature level.The body temperature was measured immediately after anesthesia,which was counted as the initial body temperature,and then the skin was routinely prepared for disinfection and the classical Higgins method was used to remove about 68% of the rat liver.during the operation,the auxiliary heating pad maintained the rat body temperature at the initial level,fluctuating less than 0.5C,and began to carry out temperature intervention after closing the abdomen.In the high temperature group,the temperature of the heating pad was raised and the heating lamp was turned on to gradually raise the body temperature to the target value of high temperature.the target temperature of the first attempt was(initial temperature + 5 ℃).According to the mortality rate to judge whether the temperature is reduced or not to explore the next target temperature.In the low temperature group,the ice was quickly cooled to the target value of low temperature(the initial temperature was-4 ℃).According to the mortality rate,it was judged whether to further increase the temperature value in order to explore the target temperature in the next step.After maintaining the target body temperature for3.5 hours,the rats were reared in a separate cage,the mortality rate was calculated,and the temperature of the lower mortality group was selected as the target temperature.2.Formal experiment: one hundred and eight clean-grade Wistar male rats were randomly divided into three groups: low temperature group,medium temperature group and high temperature group.The body temperature of the rats was measured immediately after anesthesia,which was counted as the initial body temperature,and then the skin was routinely prepared for disinfection and 68% of the livers of the rats were removed by the classical Higgins method.During the operation,the auxiliary heating pad maintained the body temperature of the rats at the initial level,fluctuating less than 0.5 ℃,and began to carry out temperature intervention after closing the abdomen.The high temperature group raised the temperature of the heating pad and turned on the heating lamp to gradually raise the body temperature to the high temperature target value(initial temperature + 3 ℃),the medium temperature group maintained the original body temperature,and the low temperature group used ice to quickly cool down to the low temperature target value(initial temperature-4 ℃).After maintaining the target body temperature for 3.5 hours,the rats were put back into a separate cage.The samples were collected at six time points of 0h-12h-24h-72h-120h-168 h after the end of temperature control.The measurement indexes included postoperative body weight,liver weight,biochemical indexes(AST,ALT,ALB,TBi L,BUN)and immunohistochemical index ki67.Results1.Pre-experiment: the target temperature(initial temperature-4 ℃)mortality rate of the low temperature group was 0%(0 beat 6),the high temperature group target temperature(initial temperature + 5 ℃)mortality was 100%(6 beat 6),the target temperature was(initial temperature+ 4 ℃)the mortality rate was 67%(4 beat 6),and the target temperature was(initial temperature +3 ℃)the mortality rate was 17%(1 hip 6).Finally,the target temperature of the low temperature group is set as(the initial temperature is-4 ℃),and the target temperature of the high temperature group is set as(the initial temperature + 3 ℃).2.Formal experiment: there was no significant difference in postoperative mortality among the three groups,and there was no significant difference in body weight growth rate among the three groups.At 24 hours after operation,the liver index in the hypothermia group was lower than that in the hyperthermia group(1.54 vs.1.88 minutes 0.032),but there was no significant difference among the other groups at other time points.There was no difference in AST,ALT,ALB and BUN among the three groups.TBi L in the hyperthermia group was higher than that in the moderate temperature group at 120 hours after operation(13.33 vs.9.41).The positive rate of Ki-67 in hyperthermia group showed better proliferation.Conclusion(1)the hyperthermia group promoted liver regeneration,and the hepatocyte proliferation in the hyperthermia group was significantly higher than that in the hypothermia group and the normothermia group at 72 hours after partial hepatectomy.(2)the hypothermia group inhibited liver regeneration,and the proliferation curve was lower and slower after partial hepatectomy than that in the normothermia group and the high temperature group.(3)There was a higher trend of total bilirubin in the hyperthermia group.