Hyperprolactinemia influences renal function in man.

Renal handling of solute and water following oral water loading was determined in six subjects with small pituitary adenomas associated with nonsuppressible hyperprolactinemia. Compared to control subjects, urine volume and solute excretion were significantly diminished in the hyperprolactinemic group. This was attributable to a decrease in osmolar clearance. Free water clearances were not different from control subjects. Hypothyroidism and adrenal insufficiency as an explanation for the antidiuresis were excluded in each patient. The data supports the suggestion that prolactin influences renal function in man.