Proximal tubule Proximal tubule Proximal tubule proximal tubules proximal tubules proximal tubules Proximal tubule proximal convoluted tubule PT English proximal Proximal tubule English proximal tubules PT Wikipedia article "Proximal_tubule" English Wikipedia article "Proximal_tubule" PT Source proximal convoluted tubule PT English проксимального извитого канальца proximal tubules