DR. MOHD NAZAM ANSARI

 Some of pathological conditions associated with retention of sodium and water in the body e.g. Congestive Heart failure, Pulmonary edema, renal edema and hypertension.  Diuretics are the drugs that causes a net loss of Na + and water in urine.  The first important site with regard to renal function is the glomerulous itself. Drugs which increase glomerular filteration rate (Xanthines, cardiac glycosides, saline) produces diuresis.

 In summary, three processes occurring in successive portions of the nephron accomplish the function of urine formation:  Filtration of water and dissolved substances out of the blood in the glomeruli and into Bowman's capsule;  Reabsorption of water and dissolved substances out of the kidney tubules back into the blood (note that this process prevents substances needed by the body from being lost in the urine);  Secretion of hydrogen ions (H + ), potassium ions (K + ), ammonia (NH 3 ), and certain drugs out of the blood and into the kidney tubules, where they are eventually eliminated in the urine.

The different classes and key prototypes of diuretics include:  Osmotic diuretics:  Mannitol  Carbonic anhydrase inhibitors:  Acetozolamide  Loop diuretics or the high ceiling diuretics:  Furosemide, Torsemide, Bumetanide, Ethacrynic acid  Thiazide and thiazide-like diuretics:  Hydrochlorothiazide, Chlorthalidone, chlorothiazide, Metolazone  K+ sparing diuretics:  Na + channel inhibitors:  Na + channel inhibitors: amiloride, triamterene  Aldosterone receptor antagonists:  Aldosterone receptor antagonists: spironolactone, eplerenone

Albino rats of either sex weighing between g are fasted (deprived of food & water) overnight and saline is administered orally. These rats are divided into three groups as follows: 1.Only normal saline 2.Saline + Urea 3.Saline + Furosemide After administration of drugs, rats are placed in the three different metabolic cages. Urine is collected in measuring cylinder. Time when the first drop of urine is collected in a cylinder for each group is noted and the volume is recorded at intervals of 15 min for 3-4 Hours. The difference in the volume collected at different time interval and total volume can be compared with various diuretics.

IIIIIIGroups After 15 min Amount of urine collected ( ml ) After 30 min After 1 Hr Total volume

 Calculate percentage increase in volume of urine taking control value as 100%.  Plot dose response curve taking log doses on X- axis and Percentage response on Y-axis.