FIG. 7.

Coculture exposure for 24 h enhances myotube insulin response. Primary human skeletal myotubes from lean (A–D) and severely obese (E–H) women were maintained 24 h in the absence or presence of human adipocytes under basal or stimulated (100 μmol/L IBMX) conditions. Adipocytes were removed, and myotubes were washed and incubated with α-MEM ± 100 nmol/L insulin for 10 min. Protein extracts were used for immunoblot analysis of Akt Ser⁴⁷³ phosphorylation, corrected for total protein loading using Memcode staining. Measurement of total Akt protein showed no treatment effects. Rates of glycogen synthesis were measured after a 2-h incubation with α-MEM containing 5 mmol/L [¹⁴C]glucose ± 100 nmol/L insulin. Results are expressed as mean ± SEM and representative of at least three experiments performed in triplicate. *Significant (P < 0.05) effect of adipocyte exposure analyzed by Student t test.