[Microcirculation in renal interstitium]

Abstract

Microcirculation in the renal interstitium plays an important role in the regulation of urinary sodium excretion and thus in the control of blood pressure. An increase in renal interstitial hydrostatic pressure caused by renal perfusion pressure elevation induces pressure natriuresis by decreasing tubular reabsorption. Chronic NO inhibition in the medullary interstitium decreases medullary blood flow and induces sodium retention and blood pressure elevation. Chronic medullary, but not intravenous, infusion of ACE inhibitor restores the impaired pressure natriuresis by improving medullary microcirculation in SHR. The tubuloglomerular feedback signal transmission is dependent on Cl concentration in the juxtaglomerular interstitium and its sensitivity is modulated by pressure there in.