A Comparison of the Segmental Analysis of Sodium Reabsorption during Ringer's and Hyperoncotic Albumin Infusion in the Rat
Open Access
- 1 September 1973
- journal article
- Published by American Society for Clinical Investigation in JCI Insight
- Vol. 52 (9), 2313-2323
- https://doi.org/10.1172/jci107420
Abstract
Studies were designed to compare the segmental analysis of sodium reabsorption along the nephron during volume expansion with either 10% body weight Ringer's or 0.6% body weight hyperoncotic albumin. Total kidney and nephron glomerular filtration rate increased similarly with both, but urinary sodium excretion (12.7 vs. 4.0 μeq/min, P < 0.001) and fractional sodium excretion (5.0 vs. 1.6%, P < 0.001) increased to a greater extent with Ringer's. Fractional reabsorption of sodium in the proximal tubule was diminished in both groups but to a significantly greater extent during Ringer's (P < 0.005). Absolute reabsorption was inhibited only in the Ringer's group. Delivery of filtrate out of the proximal tubule was greater in the Ringer's studies, 45 vs. 37 nl/min (P < 0.001). However, both fractional and absolute sodium delivery to the early and late distal tubule were not significantly different in the two groups. Fractional reabsorption in the collecting duct decreased from 96% in hydropenia to 31% during Ringer's but fell only slightly to 80% in the albumin studies. Absolute collecting duct reabsorption was also greater in the albumin studies, 0.55 vs. 0.21 neq/min (P < 0.001), which could totally account for the difference in urinary sodium excretion between the two groups. 22Na recovery in the final urine after end distal microinjections was 71% during Ringer's infusion and 34% during albumin (P < 0.001). From these data we conclude that: (a) Ringer's solution has a greater inhibitory effect on proximal tubular sodium reabsorption, and (b) in spite of this effect, differences in mucosal to serosal collecting duct sodium transport are primarily responsible for the greater natriuresis during Ringer's infusion.Keywords
This publication has 23 references indexed in Scilit:
- Micropuncture study of electrolyte transport across papillary collecting duct of the ratAmerican Journal of Physiology-Legacy Content, 1973
- Studies of the Control of Plasma Aldosterone Concentration in Normal ManJCI Insight, 1972
- Catheter size as a determinant of outflow resistance and intrarenal pressureAmerican Journal of Physiology-Legacy Content, 1972
- Role of peritubule Starling forces in proximal reabsorption following albumin infusionAmerican Journal of Physiology-Legacy Content, 1972
- Nephron function during volume expansion in the ratAmerican Journal of Physiology-Legacy Content, 1972
- Effects of Acute Volume Expansion and Altered Hemodynamics on Renal Tubular Function in Chronic Caval DogsJCI Insight, 1972
- Comparative renal effects of isoncotic and colloid-free volume expansion in the ratAmerican Journal of Physiology-Legacy Content, 1972
- Effect of saline infusion on superficial and juxtamedullary nephrons in the ratAmerican Journal of Physiology-Legacy Content, 1971
- Effect of arterial hematocrit on sodium reabsorption by the proximal tubuleAmerican Journal of Physiology-Legacy Content, 1971
- PROTEIN MEASUREMENT WITH THE FOLIN PHENOL REAGENTJournal of Biological Chemistry, 1951