EFFECT OF HUMAN C-PEPTIDE ON GLUCOSE-TRANSPORT IN INVITRO INCUBATED HUMAN SKELETAL-MUSCLE

Muscle specimens from the quadriceps femoris muscle were obtained from eight healthy subjects by means of an open muscle biopsy and prepared for in vitro incubation. C-peptide at 0.5, 1.0 and 2.5 nmol/l increased 3-0-methylglucose transport by 38 % (NS), 64 % (p < 0.05), and 64 % (p < 0.05) respectively. Glucose transport increased 1.8-fold in the presence of 0.3 nmol/l of insulin (p < 0.05). Glycogen content in muscle strips exposed to C-peptide at a concentration of 1 nmol/l increased significantly by 22 % (p < 0.05). In conclusion, C-peptide stimulates the rate of 3-0-methylglucose transport in in vitro incubated human skeletal muscle strips in a dose-response manner. These observations suggest that C-peptide may contribute to the regulation of carbohydrate metabolism in human skeletal muscle.