Effects On Blood Pressure And Renal Function In One-kidney, One Clip Hypertensive Rats After Unclipping And Changes After Destroying The Renal Medulla

Objective To explore the effects of unclipping and destroying the renal medulla on blood pressure and renal function in one-kidney, one clip(1K1C)hypertensive rats and to investigate the possible mechanism. Methods The animal model of 1K1C renovascular hypertension was established with 200～220g Sprague-Dawley rats. The rats were randomly divided into 4 groups: normal group,1K group,1K1C group,1K1C+BEA group. The renal medulla was destroyed by 2-Bromoethylamine hydrobromide(BEA). They were treated with removal of the clip as an intervention method four weeks later. Blood pressure was measured with the tail-cuff method by the rat blood pressure meter of type RBP-1 and the renal function was tested by inulin cleaning rate as well. At the same time, the volume of urine flow and the changes of the electrolytes in the urine were tested. Light microscope was used to examine the pathological changes in the renal medulla and cortex of the renovascular hypertensive rats. Results 1. Compared with 1K1C group before unclipping, removal of the arterial clip reduced blood pressure rapidly. Blood pressure decreased from 185.68±2.34mmHg to 110.42±8.64mmHg in 2 hour(P<0.01). GFR increased from 0.53±0.20mL·min-1 to 2.40±0.92mL·min-1(P<0.01). Urine flow increased from 6.31±1.79μL·min-1 to 53.24±3.75μL·min-1(P<0.001). The volume of Na+ and K+ excretory in the urine increased. (Na+ from 0.62±0.33μmol·min-1 to 9.64±1.90μmol·min-1 P<0.001); (K+ from 0.50±0.13μmol·min-1 to 1.94±0.54μmol·min-1 P<0.05). Meanwhile, FeNa increased from 0.96±0.51 to 2.09±0.32(P<0.05). 2. Compared with the 1K1C+BEA group before removal of the clip, when the renal medulla was shattered by BEA, unclipping could not decrease blood pressure or improve the GFR (P>0.05). Urine flow and the volume of Na+ and K+ excretory in the urine were similar before unclipping and after...