Figure 5. Effect of the STO-609 CaMKKβ inhibitor on hyperosmolarity-induced AMPK activation and ⁸⁶Rb⁺ uptake in mouse RBCs.

Washed mouse erythrocytes were incubated at 5% haematocrit and 37°C in Hepes-buffered Krebs medium containing 11 mm glucose, with or without 10 μm STO-609 and with or without 0.3 m sucrose for 30 min. A, extracts were immunoprecipated with anti-AMPK α1-subunit antibody for AMPK assay. The results are the means ±s.e.m. of three independent experiments. B, after 30 min, initial rates of ⁸⁶Rb⁺ uptake were calculated from measurements made at 10 and 30 min in the presence and absence of 100 μm bumetanide. The results are the means ±s.e.m. of six independent experiments. *Significant difference (P < 0.05, paired t test).