Abstract

Introduction: Calcitonin Gene-Related Peptide (CGRP), a 37-amino acid peptide generated by alternative processing of primary transcripts from calcitonin gene, is broadly distributed in the peripheral and central nervous systems of vertebrate and invertebrate species. CGRP plays a main role in the neuromuscular junction. This paper investigates the effects of endurance and resistance training on the content of CGRP in the slow and fast twitch muscles. Materials and Methods: Twenty-two male Wistar rats, (age 10 mo, weight 220± 20 gr, Pasteur Institute) were randomly divided to three groups. (Control (n=7), Endurance training (n=7), and Resistance training (n=8)) and underwent 12 weeks training according to protocols. Animals of the resistance training group were housed in a metal cage with a wire-mesh tower endurance training included treadmil running), 5 days a week, 60 min/day, 30 m/min speed, for animals in this group. Forty-eight hours after last session of protocols, animals were anaesthetized. The right soleus and anterior tibialis were removed, and, tissues were immediately frozen in liquid nitrogen and kept at -70 ° C for use later. CGRP content was measured by the ELISA method. Results: For data analyses, one-way ANOVA was used. There was no significant difference between control and endurance training groups in the CGRP of slow and fast twitch muscles. However, the content of CGRP in both fast and slow twitch muscles was significantly different in the resistance training group as compared to the control group.Conclusion: That training can be a main factor for CGRP release in muscles. In addition, the type and intensity of activity probably contribute to increase in CGRP content.