动物造模,肾小管间质纤维化模型 z-bio 2021-03-26 300

　　(1) Reproduction method Adult rats weighing 250-300g were anesthetized by intraperitoneal injection of 5% chloral hydrate, and then fixed in the supine position after anesthesia. Routine disinfection and hair removal of the animal’s abdominal operation area, surgical incisions along the midline of the abdomen, followed by incision of the skin and muscles, free the kidney and ureter, use tissue forceps to hold up the middle part of the left ureter, clamp the hemostatic forceps, use 4 at both ends -No. 0 silk thread is divided into two ligation of the left ureter near the renal pelvis, cut off the ureter, and then suture the muscle and skin routinely. After the operation, the animals were kept in a single cage for observation, and they were free to drink and eat. On the 7, 14, 21, and 28 days after the operation, the animals were anesthetized and sacrificed by bleeding from the right femoral artery, and the serum was separated for biochemical determination; 1 day before the sacrifice, the rats were collected 24h urine for measurement of urine output under fasting and incontinent water conditions. Take the left kidney tissue specimen and fix it with the fixative solution, make regular tissue sections, and observe under the light microscope. Tubular interstitial lesions are judged by three parameters: protein cast and tubule expansion; interstitial inflammatory cell infiltration; degree of interstitial fibrosis. Each parameter is evaluated from 0 to 3 points: 0 points: normal; 1 point: mildly damaged; 2 points: moderately damaged; 3 points: severely damaged.

　　(2) Model characteristics After the operation of the model rats, the serum urea nitrogen and creatinine levels increased significantly in the short term (7 to 14 days after the operation); on the 21st to 28 days after the operation, the serum urea nitrogen and creatinine decreased, but The animal serum creatinine value was still higher than before operation on 28d. It shows that the renal function after unilateral ureteral obstruction (UUO) has a process of acute decompensation to gradually compensated by the contralateral kidney, and finally the contralateral kidney is also decompensated. This change is related to the body after ureteral obstruction. Changes in intrarenal pressure, renal hemodynamics and glomerular filtration pressure are related. Within 28 days after operation, there was no significant increase in 24h urine protein excretion. The results of histopathological observations under the microscope showed that at 3 days after the operation, pathological changes such as inflammatory cell infiltration, cell proliferation, and tubule dilatation had appeared in the kidney tissue. After that, the animals may develop progressive renal tubular atrophy and interstitial fibrosis, but the kidneys are small. There was no obvious pathological damage to the structure of the bulb; PAS staining showed diffuse thickening and shrinking of the tubular basement membrane in the renal tissue, and Masson staining showed obvious fibrosis in the renal cortex and the junction of the cortex and medulla. The model preparation method is simple, the preparation time is short, the reproducibility is good, the renal interstitial fibrosis develops rapidly, and the process of renal cell transdifferentiation can be observed.

　　(3) Comparative medicine. Clinically, human renal tubular interstitial fibrosis is the main pathological basis of chronic non-neoplastic kidney diseases that persist for a long time and eventually lead to chronic renal failure. It is caused by renal tubular damage, renal interstitial inflammatory cell infiltration, Fibrosis is the main feature. Due to the long clinical course of human renal interstitial fibrosis, the complicated etiology, and the limitation of pathological materials, it is difficult to conduct dynamic research on its pathological process. It is very important to establish an ideal renal interstitial fibrosis animal model for experimental research. The commonly used methods for replicating renal interstitial fibrosis animal models are mainly through drug induction, immune-mediated, subtotal nephrectomy, gentamicin renal tubular injury model, adenine-induced fibrosis model, unilateral ureteral ligation, and radiation injury A variety of methods have been established, such as infection and infection, but these methods have their own limitations in terms of pathological characteristics of the model, modeling time and experimental cost. In view of clinical ureteral obstruction is one of the common causes of renal fibrosis. Unilateral obstructive nephropathy caused by unilateral ureter ligation in rats is a mature model for studying renal interstitial fibrosis. This model surgery usually uses the rat’s back into the abdomen, the ureter is identified by walking the renal pedicle and ureter, and the junction of the renal pelvis and ureter is ligated. Studies have also reported that the lower abdominal ligation of the lower ureter can also be used to prepare a rat model of unilateral ureteral obstruction, and the complications are significantly lower than those of conventional procedures, the operation is simple, the time is short, and the survival rate is high. The renal interstitial fibrosis model established by unilateral ureteral ligation has pathological features similar to those observed in patients with post-obstructive nephropathy. Compared with other animal models of renal interstitial fibrosis replicated by other methods, the model preparation method is relatively simple. There is good repeatability, and fibrotic lesions occur rapidly. This model has good practical value for studying the clinical mechanism of renal fibrosis and drug treatment.