Correlation of pain threshold and the intensity of traumatic stress reaction in rats

LIANG Yu-jie; Gu Wan-jie; LAI Jian; JI Jie-mei; LIU Jing-chen

doi:10.3969/j.issn.1002-266X.2014.38.010

Abstract：Objective To investigate the correlation between pain threshold and the intensity of traumatic stress reac-tion in rats.Methods A total of 100 adult SD rats were randomly divided into two groups (50 rats in each group), which were experimental group and control group.Rats in experimental group were measured blood pressure, heart rate and tail-flick latency ( TFL) , then were adopted amputation wound model by the method of amputate after 30 minutes.Thirty mi-nutes later, blood pressure and heart rate were measured again;TFL was tested;serum norepinephrine ( NE) , malondial-dehyde ( MDA) level and superoxide dismutase ( SOD) activity were detected.Rats in control group did not adopt wound model and were tested the same experimental subjects at the same time as experimental group.The correlation between pain threshold and average blood pressure, heart rate changes, correlation between serum NE and MDA content, SOD activity were analyzed by method of Pearson correlation test.Results The difference of pain threshold was not statistically signifi-cant between the two groups.The difference of average blood pressure and heart rate in control group was not significant. The average blood pressure and heart rate after amputation in experimental group were higher than amputation before as well as that in control group (P<0.05).Serum NE, MDA content and SOD activity in experimental group were higher than that in control group (P<0.05).In experimental rats group, pain threshold was negatively correlated with the difference of average blood pressure and heart rate changes before and after amputation.In experimental rats group, serum NE content was negatively correlated with MDA content and SOD activity.Conclusion The pain threshold was negatively correlated with the intensity of traumatic stress reaction, which means the lower pain threshold, the more intensity of traumatic stress reaction.