The protein tyrosine kinase-dependent pathway mediates the effect of K intake on renal K secretion.

Dietary K intake plays an important role in the regulation of K secretion: a decrease stimulates and an increase suppresses kidney expression of protein tyrosine kinase (PTK), which plays a role in regulating Kir1.1 (ROMK), which is responsible for K secretion in the cortical collecting duct (CCD) and K recycling in the thick ascending limb. Tyrosine phosphorylation of ROMK channels increases with low dietary K and decreases with high dietary K. Moreover, stimulation of tyrosine phosphorylation of ROMK1 enhances ROMK1 internalization and reduces the K channel number in the cell surface in the CCD.