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Distal Tubule H⁺ Pump & Renal Tubular Acidosis

Interactive 2D model of an α-intercalated cell's H⁺-ATPase pumping protons into the tubule lumen against a rising concentration gradient: dial pump activity and blood acid load and watch the live urine-pH curve show why a failing pump plateaus at a higher minimum urine pH no matter how much acid the blood carries — the diagnostic signature of distal (Type 1) renal tubular acidosis.

Medicine & Biophysics2DAdvanced60 FPS📱 Mobile-adapted⇄ 3D version

This 2D cross-section shows a single α-intercalated cell of the renal collecting duct actively pumping protons across its apical membrane into the tubule lumen with an ATP-driven H⁺-ATPase, working against a luminal concentration that keeps climbing the harder the pump pushes. A live urine-pH-vs-time curve integrates the same active-transport kinetics used in the 3D version of this simulator every frame: drag the pump-activity slider down (or hit the Type 1 RTA preset) and watch the achievable minimum urine pH rise and plateau — no amount of blood acid load can push it back down, because the ceiling belongs to the pump, not the acid supply. That is the mechanistic reason distal RTA patients pass alkaline urine even while genuinely acidotic.

⚙ Under the hood

Watch α-intercalated cells pump protons into the collecting-duct lumen via H⁺-ATPase, buffer them with ammonia, and leak them back through tight junctions -- dial pump activity, ammonia supply and backleak to reproduce the alkaline-urine-despite-acidemia signature of distal (Type 1) renal tubular acidosis.

nephrologyacid-basekidneyphysiologyrenal-tubular-acidosision-transport

2D · HTML5 Canvas 2D · 60 FPS target · runs fully client-side, no install