Pancreatic islet insulin secretion is increased following
resistance exercise in rats.
Fluckey, James D., William J. Kraemer, and Peter A. Farrell.
Noll Physiological Research Center and the Center for Sports
Medicine, The Pennsylvania State University, University Park, PA
16802
APStracts 2:0225A, 1995.
The purpose of this study was to determine whether or not four days of
resistance exercise facilitated insulin secretory adaptations at the
level of the pancreatic islets. Eighteen male, 400 g Sprague-Dawley
rats were randomly assigned to two groups. All animals were operantly
conditioned to engage in a resistance exercise protocol which
required full extension of the hindlimbs. Resistance was applied to
the animals via a leather and velcro vest to which weighted pouches
were attached. The acute group (ACUTE; n=9) engaged in four exercise
sessions (50 reps each) with increased resistance for each session
(70 - 120 - 120 - 190 g). Sessions were separated by 48 h rest. The
nonexercised (NONEX; n=9) group engaged in the same protocol without
resistance. Islets were dispersed 16 h postexercise, incubated for 48
h and perifused (15-20 islets . rat-1) with a medium containing
either 10 mM L-arginine or 16 mM glucose as the insulin secretagogue.
Basal insulin secretion from the islets prior to the introduction
-arginine or 16 mm glucose was the same for the ACUTE and NONEX groups
(p>0.05). The total insulin response to 10 mM arginine was
significantly higher for ACUTE vs. NONEX (1.16+0.30 vs. 0.31+0.10 ng
insulin . islet-1 . 25 min-1, respectively; p<0.05). There were no
differences between groups for the overall insulin response to
glucose (p>0.05). However, the late phase insulin response to
glucose was higher for the ACUTE group (p<0.05). These data suggest
that insulin secretory adaptations occur at the level of the
pancreatic islets following four days of resistance exercise.
Received 13 February 1995; accepted in final form 11 May 1995.
APS Manuscript Number A162-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 30 May 1995.