HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Barraclough, M. A. Articles by Jones, N. F. Search for Related Content PubMed PubMed Citation Articles by Barraclough, M. A. Articles by Jones, N. F.

1. The relationship between osmolal clearance (C_osm) and the reabsorption of solute-free water by the kidney (T_H2O^c) was examined during 10% mannitol and 2·3% saline diuresis in normal and potassium-depleted rabbits.

2. In normal rabbits at osmolal clearances close to 3·0 ml./min, T_H2O^c during mannitol diuresis was 0·87 ± 0·06 ml./min and during saline diuresis 1·19 ± 0·07 ml./min. The mean difference in T_H2O^c of 0·32 ± 0·05 ml./min was highly significant (P < 0·001).

3. In one group of potassium-depleted rabbits with a reduction in maximal urinary concentration, T_H2O^c during both mannitol and saline diureses was reduced significantly below normal and the increment in T_H2O^c normally seen during saline diuresis was abolished.

4. In a second group of potassium-depleted rabbits maximal urinary concentration (1253 ± 88 m-osmole/kg H₂O) was not significantly different from that in normal rabbits (1272 ± 116 m-osmole/kg H₂O). In these animals, T_H2O^c at osmolal clearances close to 3·0 ml./min was not significantly different during mannitol diuresis (0·83 ± 0·07 ml./min) from that in normal animals, whereas it was reduced significantly during saline diuresis (0·89 ± 0·07 ml./min, P < 0·001) and the difference in T_H2O^c normally seen between mannitol and saline diuresis was abolished.

5. The inability to increase T_H2O^c during saline diuresis above that achieved during mannitol appears to be the earliest manifestation of the concentrating defect associated with potassium depletion. It probably results from an impairment of sodium transport by the ascending limb of the loop of Henle. This is supported by the fact that potassium-depleted rabbits excreted a greater percentage of the filtered load of sodium than did normal controls.