Investigation Of Urolithiasis In Dogs And Cats And The Effect Of Metabolic Syndrome On Renal And Bladder Function In Rats

Urolithiasis is a common medical disease that endangers the health of dogs and cats.The incidence of urolithiasis is increasing year by year,and so is the incidence of obesity in dogs and cats.Medical studies have shown that metabolic syndrome(MS)develops on the basis of obesity and adversely affects multiple systems,including the urinary system.In this study we investigated the incidence of urolithiasis in dogs and cats,the occurrence of MS and its relationship with urolithiasis,and established a rat MS model to explore the effects of MS on renal and bladder functions.Test Ⅰ.Investigation of urolithiasis in dogs and cats: 174 cases of urolithiasis in dogs and 85 cases in cats were investigated.The results showed that poodle(9.77%),Pomeranian(9.77%),and schnauzer(9.20%)were susceptible breeds in dogs,Chinese garden cat(23.53%)and British shorthair cat(10.59%)were susceptible breeds in cats.Struvite was the most common stone in the urolithiasis of dogs and cats,followed by calcium oxalate stone.Obese dogs accounted for 11.49%(20/174),and obese cats 9.41%(8/85);2.30%(4/174)dogs and 8.24%(7/85)cats had MS.Test Ⅱ.Rat MS modeling: In this experiment,SD rats were randomly divided into two groups,control group was fed with ordinary rat diet,MS model group was fed with high fat diet.The test lasted for 10 weeks.Results:the body weight,body length,abdominal circumference,LEE’s index,GLU,TG and TC of RATS in MS group were significantly higher than those in control group.According to MS diagnostic criteria,the success rate of modeling in MS rats was 73.33%.Test Ⅲ.Effect of MS on renal calcium oxalate stone formation in rats: After MS modeling,the control group was divided into two groups:control group(NC)and NC inducing calculus group(NIC).The established MS group was divided into MS control(MC)group and MS inducing calculus group(MIC).NIC and MIC groups were administered with ethylene glycol and ammonium chloride to induce kidney calcium oxalate stones,and NC and MC groups were administered with water,the test lasted for 4 weeks.Urine index,serum index and renal tissue oxidation/antioxidant index were detected during the test.At the end of the test,renal histological and immunohistochemical indicators were examined.Results: Urine oxalic acid in MIC group was significantly higher than that in NIC group on day 14.Serum urea nitrogen(BUN)and creatinine(Cr)in MIC group and NIC group were significantly higher than those in NC group,and BUN and Cr in MIC group were significantly higher than those in NIC group,while these two indexes were almost the same in NC and MC groups.The serum MDA of MC group and MIC group was significantly higher than that of NC group,and also of NIC group.SOD,CAT,GSH and T-AOC of kidney tissue in MIC group were significantly lower than those in NIC group,the MDA of kidney tissue in MIC group was significantly higher than that in NIC group.The damage of renal tissue structure and calcium oxalate deposition were the most serious in MIC group,followed by NIC group.The expression of NF-κBp65 and IL-6 in the kidney of MIC group was higher than that of NIC group.The results showed that MS rats were more susceptible to nephrolithiasis and the mechanism was related to tissue oxidative stress and inflammatory changes.Test Ⅳ.Effects of MS on bladder function injury in MS rats and NAC intervention effect: After MS modeling,the control group was still used as control group(NC),the MS group was divided into three groups:MS group,low dose NAC(LNAC+MS)group and high dose NAC(HNAC+MS)group.Rats in LNAC+MS group and HNAC+MS group were given NAC 300mg/kg/d and 900mg/kg/d,respectively.The test lasted for 4 weeks.Serum oxidation/antioxidant indexes,bladder contraction force test were used to detect bladder function.Masson staining was used to detect bladder tissue fibrosis.The expressions of nuclear factor NF-κB,inflammasome NLRP3 and cytokine TGF-β in bladder tissue were detected by immunofluorescence.Results: 1.Serum SOD and CAT in MS group were significantly lower than those in NC group,while MDA,TG,TC and GLU in MS group were significantly higher than those in NC group.Bladder contraction force in MS group was significantly weaker than that in NC group.Masson staining showed that the bladder fibrosis of MS rats was significantly more serious than that of NC group.The levels of NF-κB,NLRP3 and TGF-β in bladder tissue of MS group were significantly higher than those of NC group.2.Serum SOD and CAT in NAC group were significantly higher than those in MS group;MDA,TG and TC in LNAC+MS group were significantly lower than those in MS group.TG,TC and GLU in HNAC+MS group were significantly lower than those in MS group.Bladder contractility of rats in LNAC+MS group was significantly higher than that in MS group.Masson staining showed that the bladder fibrosis of NAC treated rats was significantly reduced compared with that of MS rats.The expressions of NF-κB,NLRP3 and TGF-β in LNAC+MS group were significantly lower than those in MS group.The results showed that MS could cause bladder fibrosis and damage bladder function,and was related to the expression of NF-κB,NLRP3 and TGF-β.NAC can decrease GLU and lipid levels,improve antioxidant levels,alleviate bladder fibrosis and prevent bladder function impairment from MS.Conclusion: The investigation of urolithiasis in dogs and cats revealed the characteristics of the disease and found that MS was associated with urolithiasis in dogs and cats.MS can reduce the anti-injury ability of rats kidney,promote the formation of kidney stones,and damage the bladder structure and function,oxidative stress and inflammation are associated with impaired function of these organs.NAC can alleviate bladder function injury caused by MS.