Experimental studies of effects of acute renal venous congestion on renal function --with particular reference to renal arterio-venous plasma sodium difference.
Effects of acute renal venous congestion on renal function were studies. In anesthetized mongrels with intermittent or sustained elevation of the renal venous pressure produced experimentally by unilateral constriction of the renal vein, changes in renal function were investigated with the clearance method and plasma concentrations of electrolytes, protein and Ht of collected arterial and venous blood oals were divided into two groups according to the initial conditions concerning the various level of renal arterio-venous plasma sodium. In dogs (Group A) whose initial values of renal arterio-venous plasma sodium difference were not less than -1 mEq/L, the difference showed a negative tendency both during intermittent and during continuous congestion. In dogs (Group B) whose initial values of the difference were less than -1 mEq/L, the difference showed a positive tendency during renal venous congestion. (2) In dogs of Group A, i) the sodium reabsorption rate increased when renal physiological values (GFR and RPF) remained unchanged (during intermittent congestion) as well as when these values decreased (during continuous congestion). ii) The calculated "postglomerular" oncotic pressure and the sodium reabsorption rate were strongly correlated at the control period, showing a slightly less correlation during intermittent renal congestion, whereas during sustained congestion, the latter increased independently of the former. iii) The NCPF/CPAH remained unchanged or slightly increased during intermittent congestion and was remarkably elevated during sustained congestion. (3) In dogs of Group B, i) Diminution of renal functions such as GFR and RPF was prominent during renal congestin and satisfactory recovery of renal functions to the initial level did not occur even after release from congestion. ii) No significant increase of sodium reabsorption rate was obtained during continuous renal congestion. (4) The balance of sodium ion between the kidney and blood of dogs of Group A was discussed. The effects of acute renal venous congestion on renal function were divided into two groups and it was concluded that this renal arteriovenous plasma sodium difference is a most significant factor.
D000818:Animals; D003250:Constriction; D004285:Dogs; D005919:Glomerular Filtration Rate; D007668:Kidney / Q000378:metabolism / Q000502:physiology*; D009997:Osmotic Pressure; D012039:Regional Blood Flow; D012077:Renal Artery; D012082:Renal Veins / Q000502:physiology*; D012964:Sodium / Q000097:blood* / Q000378:metabolism; D014690:Venous Pressure
D012964:Sodium