Figure 4.

PKA, but not PKC, activity in HEK 293T cells is reduced by hypoxia. After 72 h of hypoxic or normoxic conditions,HEK293T cells were incubated with 10⁻⁶ M forskolin (activates PKA), 10⁻⁶ M H8 (inhibits PKA), 10⁻⁸ M milrinone (PDE-3 inhibitor), PMA (activates PKC), 10⁻⁶ M Go6983 (inhibits PKC) or diluent for 30 min. PKA (A) or PKC (C) activity measured in cell lysates, expressed as fold-change from normoxic control. TP-mediated Ca²⁺ mobilization in the presence of PKA activation or inhibition (B) or PKC activation or inhibition (D) determined using fluo-4, quantified as relative fluorescence units after baseline subtraction, normalized to maximal Ca²⁺ response. n = 4, **P < 0.001 compared with normoxic control.