UNCHANGED EXTRACTION OF ATRIAL-NATRIURETIC-FACTOR ACROSS THE CHRONIC ISCHEMIC HUMAN KIDNEY

The extractions of atrial natriuretic factor (E(ANF)) and the glomerular filtration marker Cr-52-ethylenediamine tetraacetic acid (E(EDTA)) were determined before and after intravenous injection of furosemide across each of the two kidneys during renal vein catheterization in hypertensive patients with unilateral or bilateral renovascular disease. Before administration of furosemide, E(ANF) was approximately 55% across both the more and the less affected kidney while E(EDTA) was significantly decreased across the more affected kidney. Significant lateralization of renin secretion to the more affected kidney was found, demonstrating an enhanced ipsilateral formation of renin. Administration of furosemide caused a significant decrease in E(EDTA) across the less affected kidney while the ipsilateral E(ANF) did not change. Furosemide caused no change in E(EDTA) or E(ANF) across the more affected kidney. No significant correlations were found between E(ANF) and E(EDTA). These results demonstrate that the extraction ANF is unchanged across the chronic ischemic human kidney. Furthermore, in the single kidney, changes in E(EDTA), as induced by furosemide, are not related to changes in ipsilateral E(ANF). Since the relation between simultaneously determined single kidney extractions of ANF and Cr-51-EDTA reflects the relation between the single kidney clearance of ANF and the ipsilateral glomerular filtration rate, our data indicate a dissociation between changes in the single kidney glomerular filtration rate and the ipsilateral total renal clearance of ANF.