1. Kidney Treks 2013 Rotation D2 Ashish Sharma, Erin McIntosh, Karen Hong, Elyse Sadow, Jared Maul-a-tortoise Acid-Base Module

2. Principal Cells of Collecting Duct Na + ATP K+K+ H+H+ H + ATPase Na + ATP K+K+ Na + ENaC H+H+ H + ATPase BasolateralApical Cl - Na + H+H+

3. Set-up

4. Experiment A

5. Principal Cells of Collecting Duct Na + ATP K+K+ H+H+ H + ATPase Na + ATP K+K+ Na + ENaC H+H+ H + ATPase BasolateralApical Amiloride H+H+

6. Experiment A Amiloride

7. CO 2 + H 2 O Carbonic anhydrase ATP H+H+ HCO 3 - Cl - ATP Na + K+K+ H+H+ H+H+ H+H+ H+H+ H+H+ Intercalated Cells of Collecting Duct HCO 3 - Basolateral Apical H+H+

8. Experiment A AmilorideHCO 3 -

9. CO 2 + H 2 O Carbonic anhydrase ATP H+H+ HCO 3 - Cl - ATP Na + K+K+ H+H+ H+H+ H+H+ H+H+ H+H+ Intercalated Cells of Collecting Duct HCO 3 - Basolateral Apical Acetazolamide

10. Experiment A AmilorideHCO 3 - Acetazolamide

11. You’re my boy, Tom!

12. Principal Cells of Collecting Duct Na + ATP K+K+ H+H+ H + ATPase Na + ATP K+K+ Na + ENaC H+H+ H + ATPase BasolateralApical Amiloride Bafilomycin

13. Experiment B Ringers +sulfate Amiloride HCO 3 - Bafilomycin Acetazo -lamide

14. Conclusions and Next Steps Group D1 postulated that the negative current resulted from H+ flux Amiloride Bicarbonate We proved this using direct and indirect blocking Acetazolamide Bafilomycin Explore renal tubule acidosis (RTA) using this model

15. Acid-Base Set-up SPOTTED! FACE OF IMPENDING DOOM SODIUM CITRATE AMMONIUM CHLORIDE

16. Urine pH Time (hours) pH

17. Urine pH Time (hours) pH Ashish’s emesis

18. Acid-Base Experiment: Mechanism Ions in the lumenConcentration (mEq) Na + 20 K+K+ 10 NH 4 + 59.9 (solved for) Cl - 90 HCO 3 - 0.1 Total0 Na + + K + + NH 4 + = Cl - + HCO 3 -

19. Calculations pH = pKa + log([HCO 3 - ]/[H 2 CO 3 ]) [H 2 CO 3 ] = k HCO2 *pCO 2 5.0 = 6.1 + log([HCO 3 - ]/[0.03*40]) [HCO 3 - ] = 0.1

20. Bicarbonate Juncos et al. 2000

21. Trends in Chloride Time (hours) Cl - (mEq) ASHISH!

22. Observations Acid and Base load decreased and increased urine pH respectively. We also followed up at longer time intervals to explore possible longer changes in urine composition. Base load increased bicarbonate excretion, which necessitates cation excretion to neutralize the negative charge. Acid load increased chloride excretion though it began to return to baseline by 9 hours.

23. Making dad proud…

24. Acknowledgements Dr. Schwartz Drs. McGrath Dr. MacIver Dr. Thomas Maren