运动性蛋白尿及其类型的强度依赖性

THE DEPENDENCE OF POSTEXERCISE PROTEINURIA AND ITS TYPE ON EXERCISE INTENSITY

本文研究探讨了不同强度负荷(50%,70%,90% VO_(2max))跑台运动后尿总蛋白(TP)及其各组份白蛋白(Alb)、β_2—微球蛋白(β_2—mG)、溶菌酶(Lys)、淀粉酶(Amy)、乳酸脱氢酶(LDH)、磷酸肌酸激酶(CPK)排泄率变化及尿蛋白各组份排泄率与HR、LA.VO_2、%VO_(2max)的相关性;运动性蛋白尿类型与运动强度的依赖性;观察了运动强度对肾小球滤过选择性和肾小管重吸收功能某些指标的影响。结果表明不同强度运动后即刻尿蛋白排泄率不同;当LA≥5.4mmol.L^(-1)时上述各组份排泄率才有显著增加;其中β_2—mG和Lys排泄率是指示大强度运动灵敏的生化指示;TP、Alb、β_2—mG、Lys、LDH与各强度指标均呈指数函数相关;Alb/TP与HR、LA、VO_2呈直线相关。HPLC研究表明中大强度运动后SI有显著下降(P<0.05);大强度运动后β_2-mG/Alb排泄率显著增加。小到中等强度运动后尿蛋白呈肾小球型,大强度运动后呈肾小球—肾小管混合型。

The changes of excretion rate of urinary total protein (TP), albumin (Alb), β_2-microglobulin (β_2-mG),lysozyme (Lys), amylase (Amy), LDH, CPK, creatinine (Cr) were studied on 11 health young male sub-jects at rest and after three work intensitis (50%, 70%, 90% VO_(2max)) of treadmill running exercise. Aurinary protein selectivity index (S. I.) and the ratio between Alb and TP (Alb/TP) were also measuredby HPLC. In the meantime, blood lactate (BLA), heart rate (HR), oxygen uptake (VO_2) relative maximaloxygen uptake (%VO_(2max)) were determined. The urinary samples were collected at rest and immeditely afterdifferent exercise intensities in each subject, Concentrated urinary samples were studied by SDS-PAGE. The moderate physical activity produced an increased urinary excretion of TP, Alb, LDH while β_2-mG,Lys increased but no statistical significance compared with light activity, when HR rose to 150bpm and LArose to 5.4mmol/L. The heavy intermitten load produced a Lighly increased urinary TP, Al, β_2-mG,Lys, CPK LDH, respectively, as compared with rest, light, and moderate load values, while Cr andAmy were unaffected. Urinary excretion of β_2-mG and Lys increased respectively to 178 and 147 fold compared with resting values. Light physical activity bad no effect on the excretion of those urinary proteinsand Cr. Our data for Lys, β_2-mG excretion were able to define heavy exercise intensity (>90%VO_(2max)). Exponential relationship were recorded between post-exercise venous lactate (BLA), HR, VO_2,%VO_(2max) and TP, Alb, β-mG, Lys, LDH respectively. These results showed that the major influence isthe intensity of exercise, rather than its duration, on the excretion rate of urinary proteins. There werealso good relationship between Alb/TP and LA, HR VO_2 (increased follows line curve). The selectivity index(S. I.) was significantly decreased after moderate exercise, as compared with light exercise. The resultssuggested that an increase of the glomerular permeability is dependent on exercise intensy. The β-mG/Albwas higher in urine collected after heavy exercise than that of in moderate. This implies that an impairedtubular reabsorption after heavy exercise.