Dissociated effect of sodium intake on glomerular and pressor responses to angiotensin

The influence of chronic and acute changes in sodium intake on pressor and glomerular capillary responses to angiotensin was studied. Scanning electron microscopy was used to observe the capillary changes in the superficial glomeruli. The results showed that both responses was sodium-dependent but in opposite directions. Low sodium intake diminished the pressor effect but enhanced the glomerular capillary response to administered angiotensin. On the contrary, a high sodium diet or a short perfusion of 0.9% NaC1 considerably diminished the sensitivity of the glomerular capillaries to angiotensin, whereas the systemic hypertensive effect was enhanced. Our results demonstrate that the systemic circulation and the capillaries of the superficial glomeruli react independently to angiotensin. This suggests that the superficial glomerular receptors differ from the systemic ones.