Physiological regulation of g4 ache in fast-twitch muscle: effects
of exercise and cgrp.
Fernandez, Hugo L., and Cheryl A. Hodges-Savola.
Neuroscience Research Laboratory, Research & Development
Service, Department of Veterans Affairs Medical Center, Bay Pines, FL
33504 and Departments of Neurology and Physiology & Biophysics,
College of Medicine, University of South Florida, Tampa, FL 33612
APStracts 2:0492A, 1995.
This work addresses the physiological regulation of the tetrameric
form of acetyl-cholinesterase (G4 AChe) in endplate regions of
anterior gracilis (AG) muscles from adult male Sprague-Dawley rats
subjected to short-term, low-intensity treadmill exercise.
Experiments involved analyses of : muscle AChe molecular form
activities, endogenous calcitonin gene-related peptide (CGRP) levels,
and the effect of exogenous CGRP on AChe forms following exercise.
Animals were exercised twice per day for 1 or 2 days. Daily training
sessions of 135 min (10 min walking alternating with 5 min resting)
were separated by a 105 min resting period. Results show that
exercise causes: a slight decline in endogenous CGRP; and, a
selective increase in G4 AChe that is partially reversed by treatment
with exogenous CGRP. These findings indicate that CGRP influences the
mechanism(s) by which G4 AChe in intact fast-twitch AG muscles adapts
to enhanced motor activity. They are also consistent with the
hypothesis that, in addition to ACh, neurogenic CGRP participates in
the regulation of G4 AChe at the neuromuscular junction.
Received 27 July 1995; accepted in final form 30 October 1995.
APS Manuscript Number A824-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 30 November 95