Fig. 7: Effects of extracellular K⁺ reductions on isolated tubule suspensions.

A Western blots from isolated tubule suspensions cultured for 30 min in either 6 mM or 0 mM K⁺ conditions (p = 8.5 × 10⁻⁴). B Representative Western blots from isolated tubule suspensions cultured for 30 min in indicated K⁺ concentrations (p = 0.008 for nonzero slope). C Representative Western blots from isolated tubule suspensions cultured for 30 min in indicated K⁺ concentrations with or without the mTORC2 inhibitor AZD8055 (10 μM) (p = 0.019 and <0.0001). D Representative Western blots from isolated tubule suspensions cultured for 30 min in indicated K⁺ concentrations with or without the AKT inhibitor MK2206 (10 μM) (p = 0.0069 and <0.0001 for pAKT, p = 0.044 and 0.0001 for pTSC2, p = 0.043 and 0.0092 for pmTOR, p < 0.0001 and p < 0.0001 for pP70S6K, p = 0.0078 and 0.013 for pS6, and p = 0.02 and <0.0001 for pNDRG1). E Representative Western blots from isolated tubule suspensions cultured for 30 min in indicated K⁺ concentrations with medium supplemented with either mannitol (30 mM) or BaCl₂ (10 mM) (p = 0.015 and 0.0004). F Representative Western blots from isolated tubule suspensions cultured for 30 min in 4 mM K⁺ at indicated pH. G Representative Western blots from isolated tubule suspensions cultured for 30 min in 4 mM K⁺ and pH 7.4 at indicated HCO₃⁻ concentrations. H Representative Western blots from isolated tubule suspensions cultured for 30 min in 4 mM K⁺ at indicated Cl^- concentrations (p = 0.0009 for nonzero slope). I Representative Western blots from isolated tubule suspensions cultured for 30 min in indicated K⁺ and Cl^- concentrations (p = 0.043 for nonzero slope). J Representative Western blots from isolated tubule suspensions cultured for 30 min in indicated K⁺ concentrations and either DMSO, DCPIB (10 μM), or DIDS (100 μM) (p = 0.036 and 0.0001). N = 3 per group for (A, F–I), 4 per group for (C, E), 4 per group for (D) except pmTOR for which N = 8, and 6 per group for (J). * indicates P < 0.05 by unpaired Student’s t test. # indicates P < 0.05 by one-way ANOVA followed by Tukey’s (C–E) or Dunnett’s (I, J) post-hoc test. † indicates P < 0.05 for slope being significantly different than 0. In I, post-hoc comparisons are made between the indicated group and the 10 mM K+, 110 mM Cl- group, the abundance of which is indicated by a dotted line and SEM indicated by the shaded gray area. All tests were two-sided. Data presented as mean ± sem.