Renal effects of amino acid infusions in patients with panhypopituitarism

Strong evidence indicates that a high protein diet accelerates end-stage renal disease by increasing glomerular capillary pressure subsequent to renal vasodilatation. The mechanisms underlying this vasodilatation remain undefined, but they have been suspected to be mediated by a pituitary factor. To test this possibility, we measured changes in renal plasma flow and glomerular filtration rate induced by an intravenous infusion of a solution of amino acids in two patients with panhypopituitarism. These patients exhibited changes in renal hemodynamics comparable to those recorded in nine healthy volunteers. The results do not support involvement of the pituitary gland in the acute renal response to amino acids.