INTRARENAL REGULATING MECHANISMS OF RENAL FUNCTION.
Abstract
In micropuncture experiments on rat kidneys early distal (Na+) was found to be increased after ischemia and was inversely related to GFR. In order to eliminate the influence of reduced tubular flow rate after renal ischemia, single loops of Henle were microperfused and the increase in early distal (NA+) was found to be in the same range of magnitude. The results indicate that the ability of the ascending limb of Henle's loop to establish a transtubular (Na+) gradient is reduced after renal ischemia. According to the hypothesis that GFR is regulated by (Na+) at the macula densa cells, it is concluded that reduction of RBF and GFR after renal damage is the response to decreased tubular Na+ reabsorption, and that the renin angiotensin system participates in renal vasoconstriction at the level of the juxtaglomerular apparatus. The reaction is considered as a Na+-conserving mechanism. Proximal tubular reabsorptive capacity and sodium reabsorption along Henle's loop remained unchanged at elevated peritubular or intratubular angiotensin concentration, indicating no direct effect of angiotensin upon tubular net sodium transport out of the proximal convolution and the loop of Henle. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1967
- Accession Number
- AD0818479
Entities
People
- Klaus Thurau
Organizations
- Ludwig-Maximilians-Universität München