McKeever K H, Schurg W A, Convertino V A
Am J Physiol. 1985 Apr;248(4 Pt 2):R422-5. doi: 10.1152/ajpregu.1985.248.4.R422.
The purpose of this study was to determine if the chronic hypervolemia that accompanies endurance exercise training is due only to an increase in the rate of water intake or if there were contributions from renal mechanisms. Four greyhound dogs, previously sedentary for 3 yr, were utilized. During the 28-day experiment each dog was trained on a treadmill ergometer for 14 consecutive days at 65% of its pretraining maximal work intensity. After training, plasma volume increased 472 ml (27.5%, P less than 0.05). The rate of water intake increased 328 ml/day (33%, P less than 0.05), whereas urine output increased 87 ml/day (20.8%, P less than 0.05). The mean resting 24-h values for clearance of sodium increased 0.29 ml/min (90.3%, P less than 0.05), and clearance of potassium decreased 1.51 ml/min (16.1%, NS). Glomerular filtration rate, free water clearance, and osmotic clearance were not significantly altered. These data suggest that the primary mechanism for the exercise training-induced hypervolemia in dogs is a net positive water balance via increased water consumption without significant contribution from an increase in renal water reabsorption.
本研究的目的是确定耐力运动训练所伴随的慢性血容量过多是否仅归因于水摄入速率的增加，或者肾脏机制是否也有作用。选用了4只先前已 sedentary 3年的灵缇犬。在为期28天的实验中，每只狗在跑步机测力计上以其训练前最大工作强度的65%连续训练14天。训练后，血浆量增加了472毫升（27.5%，P<0.05）。水摄入速率增加了328毫升/天（33%，P<0.05），而尿量增加了87毫升/天（20.8%，P<0.05）。钠清除率的平均静息24小时值增加了0.29毫升/分钟（90.3%，P<0.05），钾清除率降低了1.51毫升/分钟（16.1%，无显著性差异）。肾小球滤过率、自由水清除率和渗透清除率无显著改变。这些数据表明，犬运动训练诱导的血容量过多的主要机制是通过增加水消耗导致的净正水平衡，而肾脏对水重吸收的增加没有显著作用。
