Renal Pathological Changes In Rats With Acute And Chronic Hypoxia And The Effects On The Expression Of HIF-1 ? And ET-1

Objective: To observe the pathological changes of renal glomeruli,tubules and interstitium in rats under acute and chronic hypoxia environment,and to determine the expression of HIF-1 ? and ET-1 in renal tissue and serum,so as to clarify the important role of HIF-1 ? and ET-1 in renal damage in rats under acute and chronic hypoxia environment.Methods:: 36 male SD rats were randomly divided into control group(6 rats at 25 ?)and hypoxia group(24 rats at 25 ? and in low-pressure oxygen chamber with oxygen content of 10%,hypoxia exposure).The hypoxia group was raised in the low-pressure oxygen chamber of Qinghai University High Altitude medical center,which simulated the altitude of 4000 m.After 1 day,7 days,14 days and 28 days,the anesthetized animals were intraperitoneally injected with 10% chloral hydrate at 5mg/kg,and 6 animals were killed by bloodletting.Renal pathological examination: HE staining,light microscopy observation.The levels of HIF-1 ? and ET-1 in serum were measured by ELISA,and the expression of HIF-1 ? and ET-1 in kidney was measured by Western blot.Urine analyzer was used to analyze urine routine,and automatic hematology analyzer was used to measure blood routine.Results:1.Under the light microscope of pathological section,the epithelial cells of renal tubules in the 1-day group were slightly edematous,the lumen space was wide,the structure of glomeruli and renal vesicles were complete and clear,and the structure of glomerular capillary loop was clear.On the 3rd,7th,14 th and28th day,the edema of renal tubular epithelium gradually increased,the lumen space gradually narrowed,the structure of glomerulus and renal capsule gradually blurred,inflammatory cells such as lymphocytes gradually infiltrated the renal interstitium,and the number of red cells in renal vessels gradually increased.2.The difference of Hb / RBC / HCT between the normoxia group and the hypoxia group was statistically significant,in which the Hb / RBC / HCT of 3 / 7 / 14 / 28 days of hypoxia was significantly higher than that of the normoxia group(P < 0.05).3.There was no significant difference in Glu / urinary microalbumin between normoxia group and hypoxia group.The difference of BUN / Cre / UA between normoxia group and hypoxia treatment group was statistically significant;the bun of hypoxia 3 days / 7 days / 14 days / 21 days was significantly higher than that of normoxia group(P < 0.05);the cre of hypoxia 14 days / 21 days was significantly higher than that of normoxia group(P < 0.05);the UA data as a whole was statistically significant,but there was no significant difference compared with normoxia group.4.Through the statistical analysis of the serum HIF-1 ? and ET-1 indexes of rats,it can be concluded that there is statistical significance in the comparison of HIF-1 ? between the normoxia group and the hypoxia group,but only the difference between the hypoxia group and the normoxia group is statistically significant,and the hypoxia group is significantly higher than the normoxia group.There was no significant difference between the other groups and the normoxia group.No significant difference was found in ET1 as a whole,and no significant difference was found between hypoxia group and normoxia group.5.Western blot was used to detect HIF-1 ? in renal tissue.There was no significant difference between hypoxia group and normoxia group.The expression of ET-1 protein increased with the time of hypoxia.Conclusion:1.With the prolongation of hypoxia time,the renal pathological changes showed that the damage of glomerulus and renal tubules gradually increased.2.Hb,RBC and HCT were higher than those in the normoxia group.3.There was a significant difference between bun and cre,and with the increase of hypoxia time,bun and cre increased significantly,suggesting that the renal function of rats was damaged.4.The level of serum HIF-1 ? increased gradually with the increase of time,reached the peak on the 14 th day,and then decreased gradually.The level of serum ET-1 did not change before and after the observation.5.Western blot was used to detect the expression of HIF-1 ? protein in renal tissue.It can be seen that the expression level of HIF-1 ? in renal tissue was not significantly higher than that in serum with the prolongation of hypoxia time.The expression of ET-1 protein in renal tissue measured by Western blot was better than that measured by serum ET-1 concentration.