fa تحقيقي Original Paper <div><strong>ABSTRACT</strong><br> <strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Background and Objectives:</strong> We studied effects of eight weeks of resistance training and IGF-1 injection on serum level of IGF-1, IGFBP-3 and IGF-1/IGFBP-3 ratio in Wistar rats.<br> <strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Methods:</strong> We randomly divided 28 male Wistar rats into four groups of saline-injected control (C), resistance training+saline injection (RS), resistance training+IGF-1 injection (RI) and IGF-1 injection (II). Resistance training protocol consisted of climbing a ladder (three days/week with 5 reps/3 sets) while carrying a weight suspended from the tail for eight weeks. IGF-1 and saline (1.5 &micro;g/kg/day) were injected before and after exercise sessions. Serum IGF-1, IGFBP-3 and IGF-1/IGFBP-3 ratio and morphology of colorectal tissue were evaluated.<br> <strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Results:</strong> Serum IGF-1 level and IGF-1/IGFBP-3 ratio decreased in the RS group compared to the other groups (P< 0.05). Rats in the RS group had higher IGFBP-3 level than those in the II and RI groups (P< 0.05). IGF-1 injection had no effect on morphology of colorectal tissue.<br> <strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Conclusion:</strong> The resistance training reduces IGF-1 and increases IGFBP-3 levels, which might represent a link between resistance training and lower risk of colorectal cancer.<br> <strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Keywords:</strong> Exercise, <a href="https://www.ncbi.nlm.nih.gov/mesh/68015179">Colorectal Neoplasms</a>, Insulin-Like Growth Factor-1, Insulin-Like Growth Factor Binding Protein-3.</div> Exercise, Colorectal, Insulin-Like Growth Factor-1, Insulin-Like Growth Factor Binding Protein-3. 23 29 http://mlj.goums.ac.ir/browse.php?a_code=A-10-1-487&slc_lang=fa&sid=1 Babisan Askari 100319475328460014369 100319475328460014369 No Department of Sport Physiology, Faculty of Physical Education and Sport Sciences, Ferdowsi University of Mashhad, Mashhad, Iran Nahid Bijeh bijeh@ferdowsi.um.ac.ir 100319475328460014370 100319475328460014370 Yes Department of Sport Physiology, Faculty of Physical Education and Sport Sciences, Ferdowsi University of Mashhad, Mashhad, Iran Amir Rashid Lamir 100319475328460014371 100319475328460014371 No Department of Sport Physiology, Faculty of Physical Education and Sport Sciences, Ferdowsi University of Mashhad, Mashhad, Iran