Abstract: The object of the study was to investigate the effects of Creatine Monohydrate (CMH) supplementation on glucose absorption, glucose oxidation and glycogen synthesis in skeletal muscle of broilers. Nine hundred, 42 days old broilers were randomly assigned to four treatments with five replicates per treatment and 45 birds per replicate. The birds received either a no-CMH diet (0 mg kg-1), a low (250 mg kg-1), a moderate (500 mg kg-1) or a high-CMH diet (1000 mg kg-1) for 21 days. The results showed that CMH supplementation did not affect serum glucose concentration but did increase lactate concentration (linear and quadratic, p<0.001) as CMH supplementation increased. The concentration of lactate in pectoralis major showed a quadratic effect (p = 0.036) in response to increasing CMH supplementation. For the thigh muscle, the concentration of lactate presented a decreasing effect (linear, p = 0.042). Pyruvic acid in the pectoralis major increased markedly (linear, p<0.004; quadratic, p<0.003) with increasing CMH comcentration but an opposite effect to that in the thigh muscle. The HK1 mRNA abundance in the pectoralis major was decreased by CMH supplementation (linear and quadratic, p<0.001) but the HK1 mRNA abundance in the thigh muscle was increased with a quadratic effect. CMH supplementation had increased Lactate Dehydrogenase (LDH) activity in pectoralis major (linear, p = 0.003; quadratic, p<0.001) while no significant effect on thigh muscle as CMH concentration increased. Thus, it was inferred that CMH supplementation may improve glucose oxidation with distribution difference in skeletal muscle. Additionally, CMH supplementation had no effect on the Glycogen Synthase (GYS), Glucose Transporter 1 (GLUT1) and Glucose Transporter 3 (GLUT3) mRNA abundance, macroglycogen or total glycogen concentration of the breast and thigh muscles. CMH supplementation significantly increased the AMPKα phosphorylation of the pectoralis major and demonstrated a quadratic effect (p = 0.002) as CMH supplementation increased. CMH supplement did not affect the AMPKα phosphorylation of the thigh muscle but presented the same effect as the pectoralis major. The results suggested that CMH supplementation did not affect glucose uptake and glycogen storage of skeletal muscle but it accelerate the glucose oxidation in the thigh muscle or decelerate glycolysis in the pectoralis major, possibly regulated by AMPKα phosphorylation.
J.J. Zuo, W.G. Xia, J.H. Liu, A.Y. Abdullahi, L. Chen, M.H. Xia and D.Y. Feng, 2014. Effects of Creatine Monohydrate Supplementation on Glucose Homeostasis in Skeletal Muscle of Broilers. Journal of Animal and Veterinary Advances, 13: 89-97.