Kidney potassium homeostasis

Urea and electrolytes Urea (Creatinine) Sodium Potassium (hydrogen carbonate) (chloride) Serum or plasma mmoll pmol I mmoll mmoll mmoll mmoll Yes Kidney function Kidney function Fluid and electrolyte balance Potassium homeostasis Acid-base status Acid-base status... 

Chronic renal failure is a common consequence of diabetes but this case is complicated by the loss of fluid and electrolytes (sodium and potassium) due to diarrhoea and vomiting. Normally, the kidneys would respond to such a challenge and maintain homeostasis but Mrs Amin s kidneys were unable to do so. Mrs Amin was put on haemodialysis and treated to control the diabetes. 

The primary organ for the regulation of sodium, potassium, calcium, and magnesium is the kidney. An intricate series of physiological sensing elements and hormonal response mechanisms maintains homeostasis. A variety of diuretic drugs can be used to enhance urinary output of various soluble salts, primarily sodium and potassium chloride. Profuse sweating is also a pathway of excretion for soluble salts and occasionally zinc. ... 

In addition to vasodilatory responses, PGs have a number of other effects in the kidney. For example, PGs stimulate adenylate cyclase in juxtaglomerular cells, resulting in an increase in cAMP production this, in turn, increases renin release. Renin stimulates the release of aldosterone, which increases renal tubular secretion of potassium (Stillman Schlesinger 1990). PGs also enhance tubular excretion of sodium and water (Patrono Dunn 1987). By causing these effects in the kidneys, PGs can alter electrolyte homeostasis. Therefore, other renal side-effects of NSAID therapy can include hyperkalemia, hypernatremia and edema. Often these metabolic changes are not observed in individuals with normal renal function, but in the presence of pre-existing disease they can become clinically significant. 

Maintenance of fluid volume, osmolarity, electrolyte balance, and acid-base status are aU regulated in large part by the kidney. Homeostasis of sodium, potassium, chloride, calcium, magnesium, and phosphorus is altered due to changes in urinary excretion that occur in patients with impaired kidney function. A comprehensive discussion... 

The most important role in the maintenance and control (homeostasis) of potassium is played by the kidneys. Approximately 95% of absorbed potassium is lost by the body by renal excretion. As each person or animal ingests variable amounts of potassium, the kidneys must excrete and/or reabsorb amounts in proportion to the individual s need in the body. Potassium can be reabsorbed by the proximal convoluted tubules, and people with no potassium intake were... 

The kidneys are two fist-sized organs whose primary function is to generate urine for excretion of water and metabolic waste products. The kidneys not only remove accumulated nitrogen products (urea, creatinine, uric acid, and others) but also maintain homeostasis of water and electrolytes (sodium, potassium, chloride, calcium, phosphate, magnesium) and regulate acid-base balance. In addition, human kidneys perform a few endocrine and metabolic functions, such as production of the hormone erythropoietin (a hormone that stimulates blood cell production) and conversion of vitamin D to its active form. Because of the tremendous overcapacity of normal kidney function, a person can live with only a fraction of normal kidney capacity, and the 0.1% of the population who are bom with a single kidney often are not even aware of the missing kidney. 

---