1. April 2005 1 Kidney Practicals Diuresis Dr. Mona Soliman, MBBS, MSc Department of Physiology College of Medicine 1426 H

2. April 2005 2 Objectives 1. To measure the volumes and determine the composition of urine excreted by volunteers who have drunk: 1) No fluids (controls) 2) Water 3) Isotonic saline 4) Lasix 2. To be able to discuss the mechanisms by which the body excrete water and sodium

3. April 2005 3 Controls Lasix Water Saline Experimental groups

4. April 2005 4 Methods 1. Controls Emptied their bladder at 10:00 am and discard the urine Emptied their bladder at 10:00 am and discard the urine At 12:00, 12:30, 1:00, 1:30 measured the volumes of urine the produce and provide sample for analysis At 12:00, 12:30, 1:00, 1:30 measured the volumes of urine the produce and provide sample for analysis

5. April 2005 5 2. Water Emptied their bladder at 10:00 am and discard the urine Emptied their bladder at 10:00 am and discard the urine At 12:00 drank one liter of water At 12:00 drank one liter of water At 12:00, 12:30, 1:00, 1:30 measured the volumes of urine they produce and provide sample for analysis At 12:00, 12:30, 1:00, 1:30 measured the volumes of urine they produce and provide sample for analysis Methods…cont.

6. April 2005 6 Methods…cont. 3. Saline Emptied their bladder at 10:00 am and discard the urine Emptied their bladder at 10:00 am and discard the urine At 12:00 drank one liter of 0.9% saline At 12:00 drank one liter of 0.9% saline At 12:00, 12:30, 1:00, 1:30 measured the volumes of urine they produce and provide sample for analysis At 12:00, 12:30, 1:00, 1:30 measured the volumes of urine they produce and provide sample for analysis

7. April 2005 7 4. Lasix Emptied their bladder at 10:00 am and discard the urine Emptied their bladder at 10:00 am and discard the urine At 12:00 swallow lasix tablet (frusemide 40 mg) At 12:00 swallow lasix tablet (frusemide 40 mg) At 12:00, 12:30, 1:00, 1:30 measured the volumes of urine they produce and provide sample for analysis At 12:00, 12:30, 1:00, 1:30 measured the volumes of urine they produce and provide sample for analysis Methods…cont.

8. April 2005 8 Urine analysis

9. April 2005 9 Methods…cont. Urine analysis for: Urine analysis for: 1. Volume, by a measuring cylinder 2. [Na+] and [K+] by flame photometry 3. Osmolality 4. pH

10. April 2005 10 Calculations

11. April 2005 11 Calculations Calculations 1. Flow rate (ml/min) = urine volume (ml)/ time (min) 2. Total Na excretion (mM)= [Na+] x urine volume (L) 3. Rate of Na excretion (  M/min)= [Na] x flow rate Methods…cont. (Divide by 1000 to convert ml to L)

12. April 2005 12 Plot the Graph

13. April 2005 13 Mechanisms???

14. April 2005 14 Deprive of water  Plasma osmolality Stimulates osmoreceptors in hypothalamus  ADH secretion from posterior pituitary  Water permeability in late distal tubule and CD  Water reabsorption  Urine osmolarity and  urine volume  Plasma osmolarity toward normal

15. April 2005 15 Drink of water  Plasma osmolality Inhibit osmoreceptors in hypothalamus  ADH secretion from posterior pituitary  Water permeability in late distal tubule and CD  Water reabsorption  Urine osmolarity and  urine volume  Plasma osmolarity toward normal

16. April 2005 16 Isotonic Saline (0.9%)  Volume of ECF Osmolality same  Stretch on right atrium (volume receptors in right atrium)  ANP (Atrial Natriuretic Peptide)  Na+ excretion by kidneys

17. April 2005 17 ANP Actions  Blood flow to Kidneys (due to relaxation of Smooth muscles of blood Vessels)  GFR  Na+ loss in urine  Aldosterone  Na+ reabsorption in DCT (  Na+ loss in urine)

18. April 2005 18 Lasix (Frusemide 40 mg) Act on thick ascending limb of loop of Henle and blocks the Na+-K+- 2Cl- Co-transport (loop diuretic)  Na+ excretion in urine  water excretion

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