Fig. 8.

The four simulations described in Fig. 3 showing the influence of the major determinants of Na⁺ reabsorption in the proximal tubule during 3 wk of baroreflex activation. The determinants are renal sympathetic nerve activity (RSNA), renal interstitial fluid pressure (RIFP), and plasma concentrations of angiotensin II and atrial natriuretic peptide (ANP). Simulations are 1) for normal conditions (normal), 2) without suppression of renal sympathetic outflow (renal clamp), 3) without changes in cardiac autonomic activity (cardiac clamp), and 4) without suppression of renal sympathetic outflow and without changes in cardiac autonomic activity combined (renal + cardiac clamp).