Moderate Aerobic Training Inhibits Middle-Aged Induced Cardiac Calcineurin-Nfat Signaling By Improving Tgf-ß, Npr-A, Serca2, and Trpc6 in Wistar Rats

Objective: the purpose of this study was to investigate the effect of moderate-intensity training on the calcineurin/ nuclear factor of activated t-cells (nfat) pathway and factors affecting it in the middle-age wistar rats. materials and methods: in this experimental study, 40 young (n=10, 4-month-old) and middle-aged (n=30, 13-15 months old) wistar rats were included in this experimental study. all young and 10 middle-aged rats did not training and served as a control comparision; while the remaining 20 middle-aged rats were trained at moderate intensity for 4-weeks (n=10) or 8-weeks (n=10) on a treadmill (speed: 16 m/minutes, slope: 0%, distance: 830 m, duration: 54 minutes). results: calcineurin tissue expression was increased in the middle-aged control rats compared to the young control rats (p=0.001). expression of sarco/endoplasmic reticulum ca^2+-atpase (serc2a), natriuretic peptide receptor-a (npr-a), phospholamban (plb), plasma membrane ca^2+ atpase (pmca4b), and p-akt was significantly decreased in the heart tissue of middle-aged control compared to the young control rats (p=0.001). furthermore, transforming growth factor beta (tgf-β), including transient receptor potential canonical 6 (trpc6), were up-regulated in the heart tissue of middle-aged control compared to the young control rats (p=0.001). however, aerobic training inhibited this pathway and reversed all changes in the trained middle-aged rats. conclusion: aerobic training effectively inhibited the calcineurin/nfatc pathway and modulated intracellular ca^2+ levels at least partially by restoring npr-a, serca2, p-plb, and p-akt, and decreasing trpc6 and tgf-β levels.