CAFFEIN AND DIURESIS IN MAN

Abstract

Caffeine has a small diuretic effect in a healthy human subject. Besides the increased rate of water excretion, there is an increase in the rate of chloride excretion. Both increases occur also in a state of dehydration produced by taking dry food. The diuretic effect of caffeine increases in the presence of excess water in the body only when the water is taken in form of an approximately isotonic NaCl-solution. The condition of the body is then comparable to that in some pathological edemas. The diuretic effect has 2 phases: one that is completely inhibited by pituitrin, the seat of action of which has not yet been determined; another that is not affected by pituitrin, and possibly is concerned with a general disturbance of chloride and water equilibrium in the tissues.