Collecting duct water permeability inhibition by EGF is associated with decreased cAMP, PKA activity, and AQP2 phosphorylation at Ser.

Prior studies showed that epidermal growth factor (EGF) inhibits vasopressin-stimulated osmotic water permeability in the renal collecting duct. Here, we investigated the underlying mechanism. Using isolated perfused rat inner medullary collecting ducts (IMCDs), we found that the addition of EGF to the peritubular bath significantly decreased 1-deamino-8-d-arginine vasopressin (dDAVP)-stimulated water permeability, confirming prior observations.