The role of adrenal medullary catecholamines in potassium homoeostasis.

The concentration of potassium in plasma is maintained within the normal range in man by many different physiological factors. The kidney is obviously of prime importance, as demonstrated by the hyperkalaemia which develops in renal failure [ 11. Several circulating hormones are, however, also of importance in potassium homoeostasis. Insulin enhances the uptake of potassium in muscle, liver and adipose tissue [2-41. Mineralocorticoids and glucocorticoids lower the serum potassium, not only by their kaliuretic effect, but also by increasing potassium secretion from gut epithelial tissue [5, 61. It has been known for a long time that a third group of hormones, namely catecholamines, also influence potassium balance, but it is only recently that this physiological mechanism has been shown to be of clinical relevance. This review concerns the role of adrenomedullary hormones in potassium homoeostasis and the pathophysiological relevance of this in man.