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

April 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

April Controls Lasix Water Saline Experimental groups

April 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

April 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.

April 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

April 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.

April Urine analysis

April 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

April Calculations

April 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)

April Plot the Graph

April Mechanisms???

April 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

April 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

April 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

April 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)

April 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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