Refsum H E, Strömme S B
Scand J Clin Lab Invest. 1975 Dec;35(8):775-80. doi: 10.3109/00365517509095809.
Serum and urine electrolytes, creatinine, and urea were determined in 21 well-trained men, aged 21-56 years, in connection with a 70-km cross-country ski race, lasting 4.39-6.52 h, leading to slight dehydration. Although the race urine flow was low, averaging 0.41 (0.1-0.9) ml/min, the average urine concentrations of urea, Na, Ca, Mg, Cl and P were markedly lower than during the preceding night, while the concentrations of K and creatinine were higher, the total of measured solutes being 621 nmol/l, compared with 911 nmol/l during the preceding night. Decreasing urine flow and endogenous creatinine clearance were accompanied by a falling urine solute concentration, particularly when the race creatinine clearance decreased to below 70 ml/min, mainly due to a fall in the urea, Na, and Cl concentrations. Thus, a decrease in the glomerular filtration rate was accompanied by a progressive decline in the urine concentrating ability.
对21名年龄在21至56岁之间的训练有素的男性进行了血清和尿液电解质、肌酐及尿素的检测，检测是在一场70公里的越野滑雪比赛期间进行的，该比赛持续4.39至6.52小时，导致了轻度脱水。尽管比赛期间尿流率较低，平均为0.41（0.1 - 0.9）毫升/分钟，但尿素、钠、钙、镁、氯和磷的平均尿浓度明显低于前一晚，而钾和肌酐的浓度较高，所测溶质总量为621纳摩尔/升，相比之下前一晚为911纳摩尔/升。尿流率和内生肌酐清除率的下降伴随着尿溶质浓度的降低，尤其是当比赛时肌酐清除率降至70毫升/分钟以下时，主要原因是尿素、钠和氯浓度的下降。因此，肾小球滤过率的降低伴随着尿液浓缩能力的逐渐下降。
