Abstract
1. The role of water balance in the hypokalaemia of rats with diabetes insipidus (DI rats) was studied. 2. After a 3-day balance study DI rats had a lower muscle potassium content, and plasma [K+], and the urinary excretion of potassium in response to oral KCl loading was reduced when compared to normal rats. The hypokalaemia was found to be associated with elevated concentrations of potassium in renal medulla and papilla when compared to values in normal Long-Evans rats. 3. During a 9-day balance study urinary potassium excretion was higher than that of normal rats on days 1-3, but not different on days 4-9; this transient elevation was observed in DI rats on normal, high and low potassium diets. On a low potassium diet the urinary potassium excretion of DI rats fell to minimal levels, making unlikely the existence of a renal defect in potassium handling. 4. Muscle potassium content and plasma [K+] were normal after 9 days in metabolism cages. This spontaneous reversal of the hypokalaemia of DI rats was associated with increased water content of renal medulla and papilla, and decreased potassium concentration in these zones. 5. The effect of acute mild dehydration on potassium handling of DI rats was evaluated. Water deprivation for 1-8 hr was sufficient to raise the urinary potassium excretion of DI rats above that of DI rats drinking ad lib. Renal tissue [K+] was significantly increased after 8 hr of dehydration. Water deprivation also enhanced the response of DI rats to an oral KCl load. Two days of chronic dehydration in the form of water rationing also significantly enhanced the urinary potassium excretion of DI rats. 6. These data suggest that chronic mild dehydration may be responsible for the modest potassium deficiency observed in DI rats via alterations in renal tissue [K+] and consequently in urinary potassium excretion. Correction of dehydration during prolonged periods in metabolism cages may account for the spontaneous reversal of the hypokelaemic condition.
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Selected References
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- ALI M. N., CROSS R. B., PICKFORD M. Electrolyte excretion in diuretic and nondiuretic dogs. J Physiol. 1958 Apr 3;141(1):177–182. doi: 10.1113/jphysiol.1958.sp005965. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bengele H. H., Evan A., McNamara E. R., Alexander E. A. Tubular sites of potassium regulation in the normal and uninephrectomized rat. Am J Physiol. 1978 Feb;234(2):F146–F153. doi: 10.1152/ajprenal.1978.234.2.F146. [DOI] [PubMed] [Google Scholar]
- EVANS B. M., JONES N. C. H., MILNE M. D., STEINER S. Electrolyte excretion during experimental potassium depletion in man. Clin Sci. 1954 May;13(2):305–316. [PubMed] [Google Scholar]
- Elkinton J. R., Winkler A. W. TRANSFERS OF INTRACELLULAR POTASSIUM IN EXPERIMENTAL DEHYDRATION. J Clin Invest. 1944 Jan;23(1):93–101. doi: 10.1172/JCI101476. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Finkelstein F. O., Hayslett J. P. Role of medullary structures in the functional adaptation of renal insufficiency. Kidney Int. 1974 Dec;6(6):419–425. doi: 10.1038/ki.1974.127. [DOI] [PubMed] [Google Scholar]
- Gross F., Dauda G., Kazdo S., Kyncl J., Möhring J., Orth H. Increased fluid turnover and the activity of the renin-angiotensin system under various experimental conditions. Circ Res. 1972 Sep;31(9 Suppl):173–181. [PubMed] [Google Scholar]
- HIERHOLZER K. Secretion of potassium and acidification in collecting ducts of mammalian kidney. Am J Physiol. 1961 Aug;201:318–324. doi: 10.1152/ajplegacy.1961.201.2.318. [DOI] [PubMed] [Google Scholar]
- Jamison R. L., Lacy F. B., Pennell J. P., Sanjana V. M. Potassium secretion by the decending limb or pars recta of the juxtamedullary nephron in vivo. Kidney Int. 1976 Apr;9(4):323–332. doi: 10.1038/ki.1976.38. [DOI] [PubMed] [Google Scholar]
- Khuri R. N., Strieder W. N., Giebisch G. Effects of flow rate and potassium intake on distal tubular potassium transfer. Am J Physiol. 1975 Apr;228(4):1249–1261. doi: 10.1152/ajplegacy.1975.228.4.1249. [DOI] [PubMed] [Google Scholar]
- Kunau R. T., Jr, Webb H. L., Borman S. C. Characteristics of the relationship between the flow rate of tubular fluid and potassium transport in the distal tubule of the rat. J Clin Invest. 1974 Dec;54(6):1488–1495. doi: 10.1172/JCI107897. [DOI] [PMC free article] [PubMed] [Google Scholar]
- MALNIC G., KLOSE R. M., GIEBISCH G. MICROPUNCTURE STUDY OF RENAL POTASSIUM EXCRETION IN THE RAT. Am J Physiol. 1964 Apr;206:674–686. doi: 10.1152/ajplegacy.1964.206.4.674. [DOI] [PubMed] [Google Scholar]
- MUDGE G. H., FOULKS J., GILMAN J. Renal secretion of potassium in the dog during cellular dehydration. Am J Physiol. 1950 Apr 1;161(1):159–166. doi: 10.1152/ajplegacy.1950.161.1.159. [DOI] [PubMed] [Google Scholar]
- Malnic G., Klose R. M., Giebisch G. Microperfusion study of distal tubular potassium and sodium transfer in rat kidney. Am J Physiol. 1966 Sep;211(3):548–559. doi: 10.1152/ajplegacy.1966.211.3.548. [DOI] [PubMed] [Google Scholar]
- Malnic G., Klose R. M., Giebisch G. Micropuncture study of distal tubular potassium and sodium transport in rat nephron. Am J Physiol. 1966 Sep;211(3):529–547. doi: 10.1152/ajplegacy.1966.211.3.529. [DOI] [PubMed] [Google Scholar]
- Möhring B., Möhring J., Dauda G., Haack D. Potassium deficiency in rats with hereditary diabetes insipidus. Am J Physiol. 1974 Oct;227(4):916–920. doi: 10.1152/ajplegacy.1974.227.4.916. [DOI] [PubMed] [Google Scholar]
- Reineck H. J., Osgood R. W., Ferris T. F., Stein J. H. Potassium transport in the distal tubule and collecting duct of the rat. Am J Physiol. 1975 Nov;229(5):1403–1409. doi: 10.1152/ajplegacy.1975.229.5.1403. [DOI] [PubMed] [Google Scholar]
- Silva P., Ross B. D., Charney A. N., Besarab A., Epstein F. H. Potassium transport by the isolated perfused kidney. J Clin Invest. 1975 Oct;56(4):862–869. doi: 10.1172/JCI108165. [DOI] [PMC free article] [PubMed] [Google Scholar]
- URBACH J. R., PHELPS M. D., STEIGER W. S., BELLET S. Effect of water diuresis on renal excretion of certain urinary solutes in normal man. J Appl Physiol. 1953 Oct;6(4):243–251. doi: 10.1152/jappl.1953.6.4.243. [DOI] [PubMed] [Google Scholar]
- VALTIN H., SCHROEDER H. A. FAMILIAL HYPOTHALAMIC DIABETES INSIPIDUS IN RATS (BRATTLEBORO STRAIN). Am J Physiol. 1964 Feb;206:425–430. doi: 10.1152/ajplegacy.1964.206.2.425. [DOI] [PubMed] [Google Scholar]
- Valtin H. Hereditary hypothalamic diabetes insipidus in rats (Brattleboro strain). A useful experimental model. Am J Med. 1967 May;42(5):814–827. doi: 10.1016/0002-9343(67)90098-8. [DOI] [PubMed] [Google Scholar]
- Valtin H. Sequestration of urea and nonurea solutes in renal tissues of rats with hereditary hypothalamic diabetes insipidus: effect of vasopressin and dehydration on the countercurrent mechanism. J Clin Invest. 1966 Mar;45(3):337–345. doi: 10.1172/JCI105348. [DOI] [PMC free article] [PubMed] [Google Scholar]