Hinchcliff K W, McKeever K H, Muir W W, Sams R A
Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Ohio State University, Columbus 43210-1089, USA.
J Appl Physiol (1985). 1996 Oct;81(4):1550-4. doi: 10.1152/jappl.1996.81.4.1550.
We theorized that furosemide-induced weight reduction would reduce the contribution of anaerobic metabolism to energy expenditure of horses during intense exertion. The effects of furosemide on accumulated O2 deficit and plasma lactate concentration of horses during high-intensity exercise were examined in a three-way balance randomized crossover study. Nine horses completed each of three trials: 1) a control (C) trial, 2) a furosemide-unloaded (FU) trial in which the horse received furosemide 4 h before running, and 3) a furosemide weight-loaded (FL) trial during which the horse received furosemide and carried weight equal to the weight lost after furosemide administration. Horses ran for 2 min at approximately 120% maximal O2 consumption. Furosemide (FU) increased O2 consumption (ml.2 min-1.kg-1) compared with C (268 +/- 9 and 257 +/- 9, P < 0.05), whereas FL was not different from C (252 +/- 8). Accumulated O2 deficit (ml O2 equivalents/kg) was significantly (P < 0.05) lower during FU (81.2 +/- 12.5), but not during FL (96.9 +/- 12.4), than during C (91.4 +/- 11.5). Rate of increase in blood lactate concentration (mmol.2 min-1.kg-1) after FU (0.058 +/- 0.001), but not after FL (0.061 +/- 0.001), was significantly (P < 0.05) lower than after C (0.061 +/- 0.001). Furosemide decreased the accumulated O2 deficit and rate of increase in blood lactate concentration of horses during brief high-intensity exertion. The reduction in accumulated O2 deficit in FU-treated horses was attributable to an increase in the mass-specific rate of O2 consumption during the high-intensity exercise test.
我们推测，速尿引起的体重减轻会减少马匹在剧烈运动期间无氧代谢对能量消耗的贡献。在一项三因素平衡随机交叉研究中，研究了速尿对高强度运动期间马匹累积氧亏和血浆乳酸浓度的影响。9匹马完成了三项试验中的每一项：1）对照（C）试验；2）速尿未负荷（FU）试验，即马匹在跑步前4小时接受速尿；3）速尿负重（FL）试验，在此试验中，马匹接受速尿并携带与速尿给药后体重减轻量相等的重量。马匹以约120%的最大耗氧量跑2分钟。与C组相比，速尿（FU）增加了耗氧量（毫升·2分钟⁻¹·千克⁻¹）（分别为268±9和257±9，P<0.05），而FL组与C组无差异（252±8）。与C组（91.4±11.5）相比，FU组的累积氧亏（毫升氧当量/千克）显著降低（P<0.05）（81.2±12.5），而FL组则无显著差异（96.9±12.4）。FU组后血乳酸浓度增加率（毫摩尔·2分钟⁻¹·千克⁻¹）（0.058±0.001）显著低于C组（0.061±0.001）（P<0.05），而FL组后血乳酸浓度增加率（0.061±0.001）与C组无差异。速尿降低了马匹在短暂高强度运动期间的累积氧亏和血乳酸浓度增加率。FU处理马匹累积氧亏的减少归因于高强度运动试验期间单位质量耗氧率的增加。
