Effects of Captan, a fungicide, on mammalian slow‐twitch muscle

Abstract

The population exposure to pesticides is dramatically increasing in the last few decades because of the widespread uncontrolled use of pesticides especially in the developing countries. In our study, we examine the effect of 6 mg/kg of Captan, a fungicide, mixed with diet, on body weight, muscle mass, proteins content and contractile response of slow‐twitch skeletal muscles (soleus). As compared with controls placebo animals, 2 weeks of treatment induces a significant increasing in body weight (15%) and muscle mass (14%) which could be due in part to the increasing in soluble and Myofibrillar proteins content. Moreover, our results show that Captan treatment induces a decreasing by 15% in the expression of MHC I isoforms (Control: 88.7 ± 3.2 ; Captan: 75.3 ± 2.3) and an increasing in the expression of MHCII isoforms (Control: MHC IIa: 1.09 ±0.61; MHC IIb: 10.34±2.33; MHC IIx/d: 1.28±1.02; Captan: MHC IIa: 9.79±1.61; MHC IIb: 17.91±1.40; MHC IIx/d: 12.28±1.72; p<0.05; n= 10). Thus, this study shows that treatment by Captan mixed with diet can induce an effect in myofibrillar proteins of slow‐ twitch mammalian skeletal muscles by shifting in the expression of slow MHC type into fast MHC type.