Exercise 07: Determination of Diuretic Activity Flashcards
True about Diuretic
• Increases Flow of Urine
• Inhibits Reabsorption of Salt and Water
• Reduces Blood Volume
• Drugs that Act in the Kidneys
Located in the peritoneal cavity. Most important organ for excretion.
Kidney
Functions of Kidney
- Maintain Normal Fluid Volume
- Maintain Salt and Water Balance
- With 2 Endocrine Function
Responsible for the removal of metabolic waste and the maintenance of water and electrolyte balance.
Nephrons / Malphigian Bodies
Three (3) Processes in the Kidney
- Glomerular Filtration
- Tubular Reabsorption
- Active Tubular Secretion
Filtration of LMW Molecules (Molecular Weight: < 500). Normal GFR is 125 mL / min (180 L / day). GFR tells how Healthy the Kidney is. Ave Urine: 1 to 1.5 L (99% are Reabsorbed).
Glomerular Filtration
Two (2) GFR Measurements
- Inulin
- Creatinine
Fullfills Most of the Criteria Needed. Standard Reference. (–) Time Consuming.
Inulin
Clearance of __________ is used most extensively as the measurement of GFR. The byproduct of muscle metabolism.
Creatinine
Occurs in Distal Convoluted Tubule. Occurs after the Drug is Filtered through the Glomerulus and can be Active or Passive.
Tubular Reabsorption
• Weak Acid + Acidic Urine
• Weak Base + Alkaline Urine
• Weak Acid + Alkaline Urine (Vice Versa)
– Non-Ionized (Reabsorbed)
– Non-Ionized (Reabsorbed)
– Ionized (Excreted)
Occurs in Proximal Convoluted Tubule. Reabsorption of Water and Active Secretion of Some Weak Electrolyte (Weak Acids). Requires Carrier and Energy (Against Conc Gradient). Reflects the Effective Renal Plasma Flow (ERPF) 425 to 650 mL / min.
Active Renal Secretion
Drugs Used to Measure Active Tubular Secretion
P-Amino Hippuric Acid (PAH) and Iodopyracet (Diodrast)
These substances are both filtered by the glomeruli and secreted by that tubular cells.
P-Amino Hippuric Acid (PAH) and Iodopyracet (Diodrast)
Reabsorbs Glucose, Amino Acids, Sodium, Phosphate Ion, Potassium, Mg, Calcium, Chloride, and Water.
Nephrons