Figure 315

Mechanism of hypokalemia in Liddle's syndrome. The amiloride-sensitive sodium channel on the apical membrane of the distal tubule consists of homologous a, |3, and 7 subunits. Each subunit is composed of two transmembrane-spanning domains, an extracellular loop, and intracellular amino and carboxyl terminals. Truncation mutations of either the |3 or 7 subunit carboxyl terminal result in greatly increased sodium conductance, which creates a favorable electrochemical gradient for potassium secretion. Although patients with Liddle's syndrome are not universally hypokalemic, they may exhibit severe potassium wasting with thiazide diuretics. The hypokalemia, hypertension, and metabolic alkalosis that typify Liddle's syndrome can be corrected with amiloride or triamterene or restriction of sodium.

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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