Renal histologic and ultrastructural findings in psychogenic polydipsia and diabetes insipidus.

The renal biopsies of 15 patients affected by polydipsia syndromes were examined under light and electron microscopes. The authors contend that the observed renal lesions (dilatation of the glomerular loops, tubular hypertrophy and vacuolization, and basal membrane swelling) are the morphologic result of tubular hyperfunction in the service of ion reabsorption. This, in turn, is secondary to the increased GFR.