Dominant factors that govern pressure natriuresis in diuresis and antidiuresis: a mathematical model.

Dominant factors that govern pressure natriuresis in diuresis and antidiuresis: a mathematical model.
Am J Physiol Renal Physiol. 2014 Feb 19;
Authors: Moss R, Layton AT
Abstract
We have developed a whole-kidney model of the urine concentrating mechanism and renal autoregulation. The model represents the tubuloglomerular feedback (TGF) and myogenic mechanisms, which together affect the resistance of the afferent arteriole and thus glomerular filtration rate. TGF is activated by fluctuations in macula densa [Cl(-)] and myogenic mechanism by changes in hydrostatic pressure. The model was used to investigate the relative contributions of medullary blood flow autoregulation and inhibition of transport in the proximal convoluted tubule to pressure natriuresis in both diuresis and antidiuresis. The model predicts that medullary blood flow autoregulation, which only affects the interstitial solute composition in the model, has negligible influence on the rate of NaCl excretion. However, it exerts a significant effect on urine flow, particularly in the antidiuretic kidney. This suggests that interstitial washout has significant implications for the maintenance of hydration status but little direct bearing on salt excretion, and that medullary blood flow may only play a signalling role for stimulating a pressure-natriuresis response. Inhibited reabsorption in the model proximal convoluted tubule is capable of driving pressure natriuresis when the known...

Source: Am J Physiol Renal P... - February 19, 2014 Category: Urology & Nephrology Authors: Moss R, Layton AT Tags: Am J Physiol Renal Physiol Source Type: research