Gastrointestinal and renal excretion of potassium in African-Americans and White Americans.

Objective: Several studies have confirmed the remarkable observation that cumulative urinary potassium (K(+)) excretion is less in African-Americans than White Americans even when identical amounts of potassium are provided in the diet. This study was designed to examine whether this decrease in urinary potassium could be compensatory to an increase in gastrointestinal excretion of potassium in African-Americans.

Methods: Twenty-three young, healthy, normotensive participants of both sexes and races were placed on a fixed diet of 100 mEq per day of K(+) and 180 mEq per day of sodium (Na(+)) for 9 days.

Juxtaglomerular apparatus tumor: a rare, surgically correctable cause of hypertension.

Although uncommon, presentation of juxtaglomerular cell tumor is distinct and should allow a correct preoperative diagnosis in most patients. Typical clinical presentations include headaches, polyuria, or isolated, asymptomatic, severe hypertension. The diagnosis of a juxtaglomerular apparatus (JGA) tumor typically results from identification of plasma renin levels two- to sevenfold greater than the normal value.

Racial differences in potassium disposal.

Background: African Americans appear relatively potassium (K(+))-deficient compared with Caucasian Americans whether on unregulated diets or on diets controlled for K(+) content.

Methods: To determine whether extrarenal K(+) disposal was affected by race, KCl (0.5 mEq/kg in 0.