Intrarenal distribution of blood flow in diabetes insipidus: role of ADH.

FISHER, R. D., J.-P. GR~NFELD, AND A. C. BARGER. Intrarenal distribution of blood Jrow in diabetes insipidus: role of ADH. Am. J. Physiol. 219(5) : 1348-1358. 1970.-The distribution of renal blood flow was studied by the 8Kr method in trained, unanesthetized dogs with diabetes insipidus (DI) produced by hypothalamichypophysial tract section. The sites of renal vascular changes induced by DI were localized by autoradiography and by silicon rubber injection techniques. Renal blood flow was markedly increased during the initial diuretic phase following tract section. Autoradiography demonstrated that in the absence of ADH outer cortical flow was greater than normal, whereas juxtamedullary cortical flow and outer medullary peritubular flow were reduced; the vascular changes were corroborated by the arterial injection studies. ln addition, the abundant filling of the venous vasculature and glomeruli by retrograde injection of silicon rubber in dogs with DI indicated a low glomerular and postglomerular resistance. Further evidence for a renal vascular role of ADH was obtained by intrarenal infusion of minute, “physiological” amounts of Pitressin in the dog with DI. The results presented suggest that the control of preglomerular resistance may be primarily neurogenic, whereas control of glomerular and postglomerular resistance may be hormonal.