ISSN:
1432-2013
Keywords:
Hereditary Diabetes Insipidus
;
Proximal Convolution
;
Loops of Henle
;
ADH
;
Hereditärer Diabetes Insipidus
;
Proximales Konvolut
;
Henle'sche Schleife
;
ADH
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary Micropuncture studies were carried out on rats with hereditary hypothalamic diabetes insipidus, in order to measure net sodium and water reabsorption in proximal convolutions and short loops of Henle during water diuresis and ADH-induced antidiuresis. Intravenous infusion of 0.15 mU ADH per minute reduced urine flow from 74.5 μl per kidney per minute to 10.8 μl, and increased urine osmolality from 117 to 605 mOsm/kg. These changes could be reversed by stopping ADH. ADH did not alter the fractional reabsorption of fluid or the reabsorptive capacity for sodium in the proximal tubules. Nor did it change glomerular filtration rates of single superficial nephrons or of the entire kidney. Fractional reabsorption of the glomerular filtrate up to the early distal convolution was significantly higher (82.0%) in water diuresis than in antidiuresis (74.4%). Since this reabsorption remained unchanged in the proximal convolutions, the decreased reabsorption during antidiuresis must have occurred in the short loops. Fractional reabsorption of sodium up to the early distal tubule was essentially identical during water diuresis and antidiuresis, indicating that ADH does not enhance urinary concentration by increasing the reabsorption of sodium from short loops.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00586878
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