Doc: So you understand about your potassium intake? Dialysis Patient:

4. Doc: So you understand about your potassium intake? Dialysis Patient: Yeah, if I eat too many bananas my heart stops!

6. N a Cortical Collecting Duct Principal Cell Regulated Potassium Secretion Tubular Fluid Na+ K+ K+ Interstitial Fluid

7. N a Cortical Collecting Duct Intercalated Cell Regulated Potassium Reabsorption K+ ATP H+ ? K+ Interstitial Fluid

8. Factors which Influence K Secretion • Dietary Potassium and Plasma Potassium • Aldosterone • Flow Rate of the Tubular Fluid • ADH • Acid-Base Balance

10. Na+ K+ CCD Principal Cell K+ K+ N a 1 2 Potassium Secretion: Effects of Plasma K+ and Dietary K+ High K+ diet Potassium Secretion (mEq/day) Normal diet 3 4 5 6 7 8 PK(mEq/L)

11. K+ Adenal Cortex Aldosterone + FEK

12. -Vte Na+ Na+ Late Phase AR N N a a Early Aldosterone Increases Potassium Secretion Tubular Fluid K+ R A K+ Interstitial Fluid

13. K+ Na+ Physiological Range K+ CCD Principal Cell K+ K+ N a Potassium Secretion: Effects of Tubular Fluid Flow Rate High K+ diet Normal diet Potassium Secretion (mEq/day) Low K+ diet 0 10 20 30 40 50 Distal Flow Rate(nl/min)

15. Na+ ADH N a ADH Increases Apical Potassium Channels Tubular Fluid K+ Principal Cell K+ V2 Interstitial Fluid

17. Na+ K+ CCD Principal Cell K+ K+ N a 1 2 Potassium Secretion: Acute pH Effects Alkalosis, pH 7.5 Normal, pH 7.4 Potassium Secretion (mEq/day) Acidosis, pH 7.2 3 4 5 6 7 8 PK(mEq/L)

21. Loop Diuretics ECV Distal K delivery Distal Flow Aldo Distal K Secretion K Excretion

22. N a 25y/o Male with Liddle Syndrome, a Familial “Salt-Sensitive” Hypertension At Dx: BP 170/110 , PNa 140 mEq/l, PK 2.5 mEq/l , Low Renin/Aldosterone Vte- Na+ Tubular Fluid R K+