Spatiotemporal Patterns Of GCH1 Research After Rat Spared Nerve Injury

Objective: Neuropathic pain is one of the most common types of pain in clinical practice.GCH1 can mediate the occurrence of neuropathic pain by regulating relevant inflammatory factors.In this study,SD(Sprague Dawley)rats were used to build an SNI model,and the protein quantification and immunofluorescence localization technology were used to detect and observe the expression of GCH1 in the time and space of the rat model.Methods: First,the SNI model of rats was established,120 female SD(Sprague Dawley)rats were randomly divided into the normal group(24)and the SNI group(96).The behavioral changes were observed,and the mechanical crural reflex threshold and the sole thermal pain threshold of rats were detected preoperatively and postoperatively at 3,7,14 and 21 days.The L4-L6 spinal nerves of the lumbar segment of the models were selected from these five time points,and 12 models from each time point in each group were selected for quantitative detection of Western Blotting protein,and the remaining 12 models were used for immunofluorescence localization.Observe the dynamic changes and cell expression of GCH1 in the SNI model.Results:1.Mechanical withdrawal threshold : The reflex threshold of mechanical foot contraction in SNI model group was significantly lower than that in normal group at each time point(P < 0.001).In SNI model group,the reflex threshold of mechanical foot contraction began to decrease 3 days after operation(P < 0.001),and was most significant on the 7th day.The reflex threshold was stable after 21 days,but still lower than the normal value(P < 0.001).2.Thermal withdrawal threshold: The pain threshold of sole in SNI model group was significantly lower than that in normal group at all time points(P < 0.05).Compared with the SNI model group,the sole pain threshold began to decrease 3 days after operation(P < 0.05),and was the most significant on the 7th day.The posterior threshold restored to a stable level after 21 days,but it was still lower than the normal value(P <0.05).3.Quantitative detection of GCH1 Western Blotting protein:Compared between groups,GCH1 level in SNI model group was higher than that in normal group(P < 0.05);GCH1 level in SNI model group began to increase 3 days after operation(P < 0.05),and was most significant on the 7th day.After that,GCH1 level began to decrease to a stable level after 21 days,but still higher than that in normal group(P <0.05).4.Immunofluorescence localization of GCH1: In the spinal cord of normal rats,GCH1 was mainly expressed in neurons,and microglia and astrocytes could hardly be detected;but in the spinal cord of SNI pain model rats,GCH1 was not only expressed in neurons,but also increased in microglia.At the same time,the number of microglia changed with the level of GCH1.Conclusion: The development of neuropathic pain in rats is closely related to the level of GCH1 in vivo.After the establishment of SNI model in rats,the expression of GCH1 in vivo increased first and then decreased,and the overall level increased,resulting in a series of behavioral changes.At the same time,the overexpression of GCH1 can also increase the activation of microglia.As an important protein in neuropathic pain,GCH1 plays an important role in regulating the occurrence and development of pain.