Measurement of cellular AMPK activity and expression. AMPK expression decreased only during continuous (or chronic) exposure to 100 μM ARG in the presence or absence of 30 μM CMP-C or L-NAME for 7 days (A). Continuous co-incubation of cells with 100 μM ARG and 30 μM CDB for 7 days increased AMPK expression. Cells incubated short-term (or acutely) with 100 μM ARG for 2 h or when continuous co-treated with 100 μM ARG and 30 μM CDB showed increase in their AMPK activity (B). Co-incubation of cells with 100 μM ARG and either 30 μM CMP-C or L-NAME suppressed AMPK activity under all treatment conditions. n = 6. *, represents significant variation between control and treatment groups at p < 0.05. §, represents variation in treatment groups from cells treated with 100 μM ARG, at p < 0.05.