Diuretics and Renal Physiology Quiz

Aquaporins and Diuretics

• Aquaporins facilitate the movement of water from the tubule lumen (urine) into the tubule cells and then into the bloodstream.
• Spironolactone is an aldosterone antagonist that inhibits sodium reabsorption and promotes potassium retention.
• Eplerenone, Amiloride, and Triamterene are Na+ channel blockers that inhibit the action of aldosterone, leading to the excretion of Na and H.

Miscellaneous Diuretics

• Xanthine alkaloids, such as caffeine, theophylline, and theobromine, are diuretics.
• Osmotic diuretics, such as dextrose and mannose, increase urine production.
• Mercurial diuretics, such as Mercaptomerin, Meralluride, and Merthoxyline, are obsolete.

Anti-Hypertensives

• Imidazoline-1 receptor agonists, such as Clonidine, cause an antihypertensive effect.
• Imidazoline receptors are non-adrenergic receptors that can interact with alpha receptors to produce decongestant and antihypertensive effects.
• Tizanidine and Brimonidine are alpha-2 antagonists.

Backflow and Vasodilation

• Arteriolar vasodilation can lead to blood pooling in the veins.
• Backflow of blood can cause edema in organs.

Potassium-Sparing Diuretics

• These diuretics inhibit Na+ and Cl- co-transporter, leading to increased excretion of Na+ and Cl- in urine.
• They increase Ca reabsorption from the lumen-urine to interstitium blood, resulting in hypercalcemia.

Medicinal Organic Chemistry

• Site 4: Potassium-sparing diuretics are located in the collecting duct.
• Moxonidine (PhysiotensⓇ) and Remenidine are structurally related to Clonidine.

Anti-Hypertensives: Vasodilators

• Arteriolar vasodilators, such as Hydralazine, Diazoxide, and Minoxidil, stimulate outward K+ conductance, causing hyperpolarization of the membrane in vascular smooth muscles.
• Minoxidil's effect is not as effective as other vasodilators, but its side effect of growing hair is effective.

Thiazide and Thiazide-Like Diuretics

• These diuretics inhibit Co-transport System, leading to increased Na+/K+/Cl- in urine and electrolyte imbalance.
• They cause hypokalemia and can cause ototoxicity, leading to tinnitus.

Blood Flow

• Blood flow goes from the vena cava to the right atrium, right ventricle, left atrium, left ventricle, aortic semilunar valve, aorta, and then to different parts of the body.
• Backflow of blood or ineffective pumping of the right heart can lead to pooling of blood in the right side of the heart, and increased pressure in the lung blood vessels can cause fluid to leak into the lung tissues.