Morphological and physiological responses to aldosterone: time course and sodium dependence
| Autor: | James B. Wade, B. A. Stanton, M. Kashgarian, M. J. Field, G. Giebisch |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
Male
medicine.medical_specialty Time Factors Physiology Urinary system Renal cortex Sodium chemistry.chemical_element Biology Basement Membrane chemistry.chemical_compound Internal medicine medicine Animals Secretion Kidney Tubules Collecting Infusions Intravenous Aldosterone Infusion Pumps Dexamethasone Epithelial polarity Kidney Rats Inbred Strains Rats Microscopy Electron Kidney Tubules Endocrinology medicine.anatomical_structure chemistry medicine.drug |
| Zdroj: | American Journal of Physiology-Renal Physiology. 259:F88-F94 |
| ISSN: | 1522-1466 1931-857X |
| Popis: | The time course and Na+ dependence of morphological responses to a physiological elevation of aldosterone were examined in the renal cortical collecting duct. Male Sprague-Dawley rats were adrenalectomized and given a basal replacement infusion of aldosterone and dexamethasone by osmotic minipump. The animals were given additional aldosterone by either intravenous infusion or by a second implanted osmotic minipump for either 5 h or 1, 3, 7, or 14 days. Animals were fed either a Na(+)-replete or a low-Na+ diet. After these treatments we conducted a morphometric analysis on kidneys processed for electron microscopy by standard techniques. Increased aldosterone induced detectable proliferation of the basolateral membrane of principal cells after 24 h. Basolateral membrane continued to increase rapidly through 3 days of exposure and thereafter at a modest rate. Cell area and the surface density of the basolateral membrane were also increased by aldosterone treatment. The morphological response to aldosterone was markedly inhibited by maintaining animals on a low-Na+ diet. Acute exposure to elevated aldosterone levels (5 h) increased K+ secretion by principal cells without alterations in basolateral membrane area. Chronic (greater than 24 h) exposure to aldosterone induces morphological adaptations that are accompanied by further elevations in K+ secretion. |
| Databáze: | OpenAIRE |
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