Table 2.

Roles of ERK, p38 kinase, and PI3K in increased AQP-2 expression mediated by long term hypertonicity (24 h NaCl)

NaCl (mOsm/l)InhibitorAQP-2 Protein (Relative Value)
300100
300UO57 ± 7
300SB85 ± 21
400324 ± 47
400UO239 ± 7
400SB304 ± 32
300100
300Wort81 ± 13
400249 ± 33
400Wort245 ± 45
  • Confluent mpkCCDcl4 cells were pre-incubated 2 h in the presence or absence of either 10−6 mol/L UO126, 10−6 mol/L SB203580, or 10−7 mol/L wortmannin, after which time cells were treated with 10−10 mol/L AVP for an additional 2 h and then incubated for 24 h in isotonic (300 mOsm/L) or NaCl-supplemented hypertonic (400 mOsm/L) medium prior to Western blot analysis. The results are expressed as the percentage of control values determined in isotonic medium in the absence of pharmacological inhibitors and means ± SEM from four independent experiments.