PRODUCTION OF CONDITIONED DIURESIS IN MAN*

Abstract

Normal human subjects, maintained on standard schedules of hydration and activity, were conditioned by receiving 750-ml water loads in a stereotyped manner on five to fifteen occasions. Subsequently, a single 30-ml swallow produced a phasic diuresis in all subjects lasting 40 to 80 minutes. Identical 30-ml swallows taken in control experiments before conditioning had no such effect, being followed by a pattern of decreasing urine flow rates. The conditional diuresis was similar to standard water diuresis in composition. Analysis of urinary composition showed an addition of free water to the urine without significant alteration in electrolyte and creatinine excretion. The evidence implicating neurogenic suppression of antidiuretic hormone release from the neurohypophysis as the efferent mechanism for this diuresis is critically discussed. The evidence suggests that new kinds of hormonal response can be established in the human through repeated associative experience.