Gene expression of appetite regulatory factors and glucose transporters in hypothalamus, pectoralis major, abdominal fat and liver after insulin injection in chicken lines selected for high or low body weight

Abstract

Chickens selected for high (HWS) and low (LWS) body weight for 55 generations differ by 12‐fold in body weight at 8 weeks old and display differences in appetite and body composition. We hypothesized that there are differences between the lines in appetite regulatory factor and glucose transporter (GLUT) mRNA that are accentuated by exogenous insulin. Female 87–92 d old HWS and LWS were injected with insulin or vehicle and at 60 min mRNA was measured in hypothalamus, pectoralis major skeletal muscle, abdominal fat and liver. In hypothalamus, neuropeptide Y (NPY) mRNA was lower (P < 0.05) in HWS than LWS, while Forkhead box protein O1 (FOXO1) was greater (P < 0.05) in HWS. Abundance of GLUT1 and GLUT9 mRNA were greater (P < 0.05) in HWS than LWS in all tissues. The GLUT1 mRNA was greater in liver (P < 0.05) than in hypothalamus or fat. Although GLUT3 mRNA was not detected in hypothalamus or muscle, expression was greater (P < 0.05) in fat than liver. For GLUT2, GLUT8 and GLUT9, mRNA was lowest in fat (P < 0.05). In liver, insulin was associated with reduced (P < 0.05) GLUT3 mRNA as compared with vehicle. These data show differential expression of NPY, FOXO1 and glucose transporters in HWS and LWS.