Furosemide reduces accumulated oxygen deficit during brief, intense
exertion.
Hinchcliff, K. W., K. H. McKeever, W. W. Muir, and R. A. Sams.
Exercise Physiology Laboratory, Department of Veterinary Clinical
Sciences, College of Veterinary Medicine, The Ohio State University,
601 Vernon L. Tharp st., Columbus, OH 43210-1089
APStracts 3:0245A, 1996.
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
oxygen deficit and plasma lactate concentration of horses during high
intensity exercise were examined in a 3-way balance, randomized,
cross over study. Nine horses completed each of 3 trials: 1) A
control (C) trial; 2) a furosemide, unloaded (FU) trial in which the
horse received furosemide 4 hr 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% VO2max.
Furosemide (FU) increased VO2 compared to C, (P < 0.05, 268 +/-
9 and 257 +/- 9 ml.2 min-1.kg-1) whereas FL was not different to C
(252 +/- 8). Accumulated oxygen deficit was significantly (P <
0.05) lower during FU (81.2 +/- 12.5 ml O2eq.kg-1), but not during FL
(96.9 +/- 12.4), than during C (91.4 +/- 11.5). Rate of increase in
blood lactate concentration after FU (0.058 +/- 0.001 mmol.2 min
-1.kg-1), 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 oxygen deficit and rate of increase in
blood lactate concentration of horses during brief, high intensity
exertion. The reduction in accumulated oxygen deficit in FU treated
horses was attributable to an increase in the mass specific rate of
oxygen consumption during the high intensity exercise test.
Received 2 January 1996; accepted in final form 7 May 1996.
APS Manuscript Number A4-6.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 28 May 96