Figure 5. ASC and in vitro-differentiated derived adipocytes express two types of delayed rectifier K⁺ currents.

Light microscopy of a S-ASC (A), V-ASC (B), S-ADIPO (C) and V-ADIPO (D) plated on glass coverslip and impaled by the patch pipette for electrophysiological records (magnification 40X). (E–F) Typical I_K,DR trace currents elicited by a voltage step to 50 mV from a holding potential of −60 mV in Control solution with 4-AP (2 mM), Nifedipine (10 µM) and Ba²⁺(0.1 mM) in S-ASC (Ea), S-ADIPO (Eb), V-ASC (Fa) and V-ADIPO (Fb). In each cell type, I_Ks traces are obtained in the presence of Ibtx (100 nM) and I_BK traces by subtracting I_Ks from I_K,DR. By adding Chr (50 µM) only a very small residual current was recorded (Ibtx+Chr current traces). (G–J) Family of I_BK (G and I) and I_Ks (H and J) family of current traces evaluated as in panels E and F (same cells) from pharmacological dissection with voltage steps of 10 mV increments (from −80 to 50 mV; HP of −60 mV. Note the different ordinate scale in all panels.