The Mechanism Of Exercise-induced Proteinuria By Caused By NADPH Oxidase

Research objective:Although exercise-induced oxidative stress is a important reason which induced proteinuria, the sources and the mechanism of reactive oxygen species in kidney that promote it are unknown. We investigated the mechanism of exercise-induced proteinuria by a rat treadmill exhaustive exercise model. The rats were injected NADPH oxidase inhibitor apocynin on the tail. According to the changes of the kidney tissue and podocyte nephrin protein of after exhaustive exercise,further explore the mechanism of the formation of proteinuria.Research methods:Experiment one:32 SD rats were randomly divided into the control group (group C), control+ drug group (group CA), exhaustive exercise group (group E), exhaustive exercise+ drug group (group EA). The rats were administrated apocynin at 10mg/kg weight for once a day, for three days, and for one hour after the end of the drug injection, a one-time exhaustive exercise was performed. After Exhaustive exercise, urine protein, blood BUN, and kidney ROS concentration, NOS activity, NOS and 3-NT concentration were detected.Experiment two:14 SD rats were randomly divided into the control group (group C), exhaustive exercise group (group E). Three consecutive days of exhaustive exercise, start with 20m/min and 5% grade 5min; gradually increased to 24m/min,10% slope,until exhausted, we are observed the morphologic change of renal tissues by measure of urine up, uric acid, glucose, blood BUN, and ROS, iNOS,3-NT and NOX4 in kidney, and nephrin protein content and Harris staining in rats after exhaustive exercise.Research results:Experiment one:(1)After one time exhaustive exercise, UP content of group E was significantly increased compared with control group (P>0.01),the group EA significantly decreased compared with group E(P>0.05), and BUN increased both in group E and EA (P>0.05).(2) After one time exhaustive exercise, ROS content of group E was significantly increased compared with group C, group EA compared with group E was also significantly decreased.(3) After one time exhaustive exercise compared with control group, iNOS's activity increased both in group E and EA (P>0.05),there was no maked change in nNOS and eNOS's activity.At the same times, only iNOS's protein expression increased both in group E and EA(P>0.05), there was no maked change in nNOS and eNOS's protein expression.(4) After one time exhaustive exercise,the kidney 3-NT content of group E was significantly increased compared with group C (P>0.01), group EA significantly decreased compared with group E(P>0.05).Experiment two:(1) After exhaustive exercise, compared with the group C,the group E concentration increased for urine protein(P>0.01), uric acid(P>0.01), urine glucose(P>0.01).(2) After exhaustive exercise, compared with the group C,the group E concentration increased for serum uric acid, blood urea nitrogen(P>0.01), concentration decreased serum glucose(P>0.01).(3) After exhaustive exercise, the kidney of compared with the group C,the group E generated increased for ROS.(4) After exhaustive exercise, the kidney of compared with the group C, the group E significantly increased for iNOS and 3-NT protein expression, decreased for nephrin protein expression.(5) After exhaustive exercise,renal tissue Harris staining found, normal uniform and regular arrangement on glomerular morphology of rats in group C,and the group Eglomerular sphere hypertrophy, glomerular morphology change and distribution of reduced, capillary basement membrane thickening, mesangial stromal hyperplasia.Research conclusions:(1) Exhaustive exercise generated increases kidney UP?BUN?urine glucose and decreased serum glucose.(2) Exhaustive exercise increases kidney NADPH oxidase activity, reaction O2-., the activity of the enzyme was inhibited by the injection of apocynin.(3) Exhaustive exercise increases kidney iNOS's activity and protein expression.(4) Exhaustive exercise increases kidney 3-NT protein expression.We decided that exhaustive exercise create an excess of O2-. caused by NADPH oxidase, and the latter with NO generated by NOS catalytic reaction, leading to generate excessive ONOO".(5) Exhaustive exercise decreased expression of nephrin protein in the cell of podocyte, Exhaustive exercise can change the filtering structure of rat kidney.(6)Fluorescence microscopy was used to observe the damage of renal tissue in rats after exhaustive exercise, and the filtration barrier was damaged.Then we speculate that force exhaustive exercise can by increasing in renal tissue of rats with ONOO" expression induced crack pore protein of podocyte nephrin expression decreases, cause changes in the structure change of renal tissue injury, which lead to the occurrence of exercise-induced proteinuria.