Journal of Applied Physiology, Vol 68, Issue 1 241-247, Copyright © 1990 by American Physiological Society

ARTICLES

Oxygen consumption and distribution of blood flow in rats climbing a laddermill

K. I. Norton, M. T. Jones and R. B. Armstrong
Department of Physical Education, University of Georgia, Athens 30602.

The purpose of this study was threefold: 1) to determine whether untrained rats that refused to run on treadmill would climb on a laddermill (75 degrees incline); 2) to determine O2 consumption (VO2) in untrained rats as a function of laddermill climbing speed; and 3) to determine whether the circulatory response of untrained rats to laddermill climbing is similar to that previously reported for treadmill running at an equivalent VO2. Eighteen female Sprague-Dawley rats that would not perform on a treadmill as part of another study were used to measure VO2 as a function of laddermill speed (5-17 m/min). Data were obtained from all 18 rats; VO2 increased linearly as a function of laddermill speed (r = 0.83, y = 3.0 x + 63.2). Twenty-four female Sprague-Dawley rats that also refused to run on a treadmill were used to measure mean arterial pressure, heart rate, and blood flow distribution (with microspheres) during climbing at 5 and 10 m/min. These exercise intensities were metabolically equivalent to level treadmill running at 45 and 60 m/min (VO2 approximately 78 and 93 ml.min-1.kg-1, respectively). Of the 24 animals, 23 were willing to climb. Mean arterial pressures were higher (approximately 10%) during laddermill climbing than during equivalent treadmill running, but heart rates were the same. General blood flow distribution among muscles as a function of fiber type (with red muscles receiving higher flows) and between muscles and visceral tissues (muscle blood flow increased as a function of exercise intensity while visceral blood flows decreased) were similar to data for rats running on the level.(ABSTRACT TRUNCATED AT 250 WORDS)

This article has been cited by other articles:

				K. Sasaki, F. Morishita, and Y. Furukawa Peptidergic innervation of the vasoconstrictor muscle of the abdominal aorta in Aplysia kurodai J. Exp. Biol., December 1, 2004; 207(25): 4439 - 4450. [Abstract] [Full Text] [PDF]

				T. Miyauchi, S. Maeda, M. Iemitsu, T. Kobayashi, Y. Kumagai, I. Yamaguchi, and M. Matsuda Exercise causes a tissue-specific change of NO production in the kidney and lung J Appl Physiol, January 1, 2003; 94(1): 60 - 68. [Abstract] [Full Text] [PDF]

				S. Maeda, T. Miyauchi, T. Kobayashi, K. Goto, and M. Matsuda Exercise causes tissue-specific enhancement of endothelin-1 mRNA expression in internal organs J Appl Physiol, August 1, 1998; 85(2): 425 - 431. [Abstract] [Full Text] [PDF]

				S. Maeda, T. Miyauchi, M. Sakane, M. Saito, S. Maki, K. Goto, and M. Matsuda Does endothelin-1 participate in the exercise-induced changes of blood flow distribution of muscles in humans? J Appl Physiol, April 1, 1997; 82(4): 1107 - 1111. [Abstract] [Full Text] [PDF]