Tamm-Horsfall protein protects urothelial permeability barrier

Normal urine contains a cationic factor that appears to increase urothelial permeability by injuring the mucosa, allowing potassium ions to penetrate the urothelium and depolarize underlying nerves and muscle. THP appears to neutralize the LMW fraction electrostatically and attenuate urothelial damage, resulting in suppression of potassium chloride-mediated bladder hyperactivity.