Relationship of Elevated Renal Venous Pressure to Sodium Clearances and Edema Formation in Unanesthetized Dogs

Publisher Website
Google Scholar
Abstract
Serial renal and Na clearance studies in unanesthetized dogs with partial inferior vena cava ligation above the hepatic veins revealed: (1) elevated renal venous pressure; (2) depressed renal plasma flow; (3) transient reduction in glomerular filtration rate, with this function tending to return latterly to normal; (4) marked persistent failure of natriuresis and diuresis in response to an intraven. hypertonic saline load, due primarily to altered renal tubular reabsorption of sodium and water; (5) chronic retention of administered saline, with resultant augmentation of ascites formation. These alterations in renal handling of sodium and water are not attributable to either depressed glomerular filtration rate (decreased presentation of filtered Na to the renal tubules) or to elevated renal venous pressure, since a simila''r increment in renal venous pressure alone does not affect these changes. The changes in renal tubular function appear to be stimulated by the extrarenal alterations in body fluid compartments. Renal retention of Na and water acts to maintain blood volume in the face of threatening hypovolemia and hemoconcentration due to ascites formation. The mediators of this response remain obscure.