Protective Mechanism Of Dexmedetomidine On Acute Stress Induced Renal Injury In Rats Via The Regulation Of P2X₇R/NF-κB/NLRP3 Pathway

The morbidity and mortality of kidney injury caused by acute stress（AS）are increasing year by year,which seriously endangers animal health and livestock production.Due to its complicated pathogenesis,no effective prevention and treatment drugs or intervention measures have been developed yet.Therefore,acute stress has been clarified The pathogenesis of kidney injury and the search for effective prevention and treatment drugs are the current difficulties and hotspots in veterinary medicine and even medical research.Dexmedetomidine（DEX）has significant anti-oxidant,anti-apoptotic and anti-inflammatory pharmacological properties.At the same time,the previous research of the research group found that DEX can alleviate kidney damage caused by acute stress,but the specific mechanism of action is not yet complete.Therefore,this test aims to explore the mechanism of kidney damage caused by AS and the protective mechanism of DEX on the kidney.In this experiment,30 healthy male Wistar rats were selected,and they were randomly divided into 5 groups—control group（C group）,control plus DEX group（C+D group）,and acute stress group（AS group）,DEX intervention therapy group（AS+D group）and A438079 inhibitor group（AS+Y group）.The AS model was established by forced swimming for 15 minutes,and then immediately after 3 hours of restraint stress.The open field test verified that the model was successfully established and blood was collected from the heart,and kidney tissue and urine were collected.Using biochemical examination,pathological tissue section observation,urine detection,enzyme-linked immunoassay,immunofluorescence,RT-PCR,immunohistochemistry,and Western blot technology,explore the specific protective mechanism of DEX on AS-induced renal injury and Specific protective effect site.According to the results of the previous research of the research group,30μg/kg was selected as the DEX dose.This test performed tests to assess renal function,histopathological observations,oxidative stress,urine tests,urine ATP levels and inflammation indicators.In previous experiments,it was found that DEX can significantly inhibit the expression of P2X₇receptors.Therefore,the P2X₇R inhibitor（A438079）was used for further experiments to explore whether DEX can protect the rat kidney injury caused by AS by inhibiting the P2X₇R/NF-κB/NLRP3pathway.In subsequent experiments,immunofluorescence localization was performed on the expression of P2X₇,and the expression and expression level of P2X₇in renal glomeruli and renal tubules were clearly observed.Western Blot results showed that the expression of P2X₇protein in the AS group was significantly increased compared with that in the C group（p<0.01）,and the DEX treatment group was significantly decreased,which was consistent with the immunofluorescence results.Kidney histological observation results:No abnormalities in group C rats,multiple focal renal hemorrhage,neutrophil infiltration,focal renal tubular necrosis,and vacuolar degeneration were found in the kidney tissue of rats in group AS.In group AS+D No obvious damage was observed,and it was significantly relieved relative to the AS group.Urine test results showed that the occult blood and urine protein content of AS group increased significantly（p<0.01）,and the urine ATP content of AS group increased significantly（p<0.01）,which was consistent with the results of kidney injury observed in pathological sections.Kidney damage caused by acute stress increased the expression levels of P2X₇,NLRP3 and phosphorylated NF-κB protein（p<0.01）,and also significantly increased the m RNA expression levels of IL-1β,IL-18 and TNF-α（p<0.01）.Both DEX and P2X₇inhibitors reduced the protein levels of P2X₇R,NLRP3 and p-NF-κB（p<0.01）,and also reduced the m RNA expression levels of IL-1β,IL-18 and TNF-α（p<0.01）,There was no significant difference between the AS+D group and the AS+Y group（p>0.01）.These studies have shown that AS induces renal inflammation by activating the P2X₇R/NF-κB/NLRP3 pathway.DEX significantly improves AS renal insufficiency,reduces inflammation and oxidative stress,thereby improving AS-induced renal damage,which is similar to P2X₇.The effect of the body inhibitor group is the same.Comprehensive analysis test results show that AS can cause the body’s extracellular ATP level to increase rapidly,which in turn activates the purinergic receptor P2X₇R,triggers the NF-κB signaling pathway,induces NLRP3 activation,and causes kidney inflammatory damage.DEX can effectively reduce inflammation and oxidative stress by inhibiting the P2X₇R/NF-κB/NLRP3 signaling pathway,thereby alleviating the kidney damage caused by AS.DEX has a protective effect on kidney damage caused by AS,and P2X₇R is a potential therapeutic target in the treatment of kidney damage caused by acute stress.