Blood flow response to treadmill running in the rat spinotrapezius
muscle.
Musch, Timothy I., and David C. Poole.
Departments of Kinesiology and Anatomy/Physiology, Kansas State
University, Manhattan, KS 66506-5602
APStracts 3:0415H, 1996.
The rat spinotrapezius muscle has been utilized to investigate the
microcirculatory consequences of exercise training. It was the
purpose of this investigation to determine whether, and to what
extent, this muscle is recruited during treadmill exercise.
Radioactive 15 [mu]m microspheres were used to measure blood flow to
the spinotrapezius and hindlimb musculature as well as the abdominal
organs of female Wistar rats. Blood flows were measured at rest and
during two levels of treadmill running exercise (i.e., 0% grade - 15
m/min; 10% grade - 24 m/min). As expected, exercise increased blood
flow to the soleus, plantaris, red gastrocnemius, mixed gastrocnemius
and white gastrocnemius muscle, whereas blood flow to the stomach,
intestines, pancreas, spleen and kidneys was decreased
(P<0.05). However, contrary to our expectation, blood flow to
the spinotrapezius muscle decreased from 61+6 ml/100 g/min at rest to
39+2 ml/100 g/min at 0% grade - 15 m/min and 46+4 ml/100 g/min at 10%
grade - 24 m/min (p<0.05). These findings support the premise
that treadmill running does not recruit the spinotrapezius muscle and
suggest that previous training-induced arteriolar adaptations
produced in this muscle may result from mechanisms unrelated to
augmented exercise blood flow or muscle metabolism.
Received 6 August 1996; accepted in final form 17 September 1996.
APS Manuscript Number H705-6.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 5 November 1996