Physiological Working of Osmotic Diuretics
The renal proximal tubule is the primary site of action of osmotic diuretics.
Normally, water molecules follow Na+ out of the proximal tubule, resulting in Na+ and water reabsorption. When osmotic diuretics are introduced, they hold onto water molecules in the tubule. Since the luminal membrane is quite leaky to Na+, this causes a high back leak of Na+ into the tubule.
Na+ is normally followed by K+ and Cl- out of the proximal tubule. When there is high back leak of Na+, these electrolytes stay in the tubule and are lost through urine.
Note: Glucose is completely reabsorbed by the kidneys but not Mannitol.
Read more about this topic: Osmotic Diuretic
Famous quotes containing the words working and/or osmotic:
“... probably all of the women in this book are working to make part of the same quilt to keep us from freezing to death in a world that grows harsher and bleaker—where male is the norm and the ideal human being is hard, violent and cold: a macho rock. Every woman who makes of her living something strong and good is sharing bread with us.”
—Marge Piercy (b. 1936)
“Life begins at six—at least in the minds of six-year-olds. . . . In kindergarten you are the baby. In first grade you put down the baby. . . . Every first grader knows in some osmotic way that this is real life. . . . First grade is the first step on the way to a place in the grown-up world.”
—Stella Chess (20th century)