Preliminary Study On The Anti-fibrosis Effect Of Nintedanib In A Modified Rat Model Of Neurogenic Bladder

Objective: To establish a stable and reliable rat neurogenic bladder(NB)model and further explore the role of a new anti-fibrosis drug,Nintedanib(NIN),in improving NB fibrosis and urination dysfunction based on this animal model.Methods: Thirty female SD rats were randomly divided into Sham group(n=10),Neurogenic bladder group(NB,n=10),and NIN treatment group(n=10).The NB model was initially established by cauda equina disconnection.The survival rate and stability of this model were improved by body surface marker location,postoperative infection prevention and assisted urination,etc.The urodynamic assay was used to evaluate physical bladder functions.HE staining was used to detect the pathological changes of bladder tissue.Masson and Sirius red staining were used to assess collagen deposition and fibrosis.Immunohistochemical staining and Western blot were used to detect the expression levels of Collagen-I(Col-I)and Collagen-III(Col-III)proteins.Results: 1.After cauda equina transaction,rats in both NB group and NIN group showed urinary dysfunction,which was mainly reflected in lower abdomen and enlarged bladder and more expelled urine when pressing the abdomen of rats,and 14 rats had hind limb paralysis at the second day after operation.Fifteen rats survived in NB group and NIN group(75% survival rate)while all rats in Sham group survived.2.Urodynamic assay:there was no significant difference in bladder capacity between NB group and NIN group(p=0.227).The bladder capacity of the NB group was significantly higher than that of the Sham group(p< 0.001).Detrusor leak point pressure in the NIN intervention group was significantly lower than that the in NB group(p < 0.05)The Sham group had no urine leakage point and could urinate reflexively.3.Pathological changes of bladder: The bladder wet weight in NB group was significantly higher than that in Sham group(p<0.001).The NIN group had a significantly lower bladder wet weight than the NB group(p<0.001).ompared with Sham group,the rats in NB group had increased bladder volume,proliferation of blood vessels,disorder of muscular layer of bladder wall,and thickening of mucosa.Morphologically,the thickness of bladder wall in the NB group was significantly higher than that in the Sham group(p< 0.001).he thickness of bladder wall in NIN group was significantly lower than that in NB group(p<0.01).4.Changes of bladder fibrosis: The degree and area of bladder fibrosis in NB group were significantly higher than those in Sham group(all p< 0.001),and the counterpart in NIN group was significantly lower than that in NB group(all p< 0.05).The results of Sirius red staining,immunohistochemical staining,and Western blot showed that the protein levels of Col-I and Col-III in NB group and NIN group were higher than those in Sham group,and the counterpart in NIN group were lower than those in NB group.Conclusion: Based on the spinal cord injury NB rat model,a stable NB fibrosis model was established through transecting the cauda equina nerve and refining and improving the model operation and postoperative nursing details.2.Nintedanib could significantly slow down the progression of bladder fibrosis in NB rats and improve the urodynamics.