Role of corticosteroids in distal acidification of amiloride-treated rats
The role of amiloride-dependent sodium channels in the action of adrenal cortical steroids on urine-blood PCO2 (U-B PCO2) differences was studied in bicarbonate-infused and amiloride-treated adrenalectomized rats. U-B PCO2 was significantly reduced by amiloride in bicarbonate-infused control rats. A...
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| Autores principales: | , , , , |
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| Formato: | JOUR |
| Materias: | |
| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_00084212_v70_n5_p695_Ansaldo |
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| Sumario: | The role of amiloride-dependent sodium channels in the action of adrenal cortical steroids on urine-blood PCO2 (U-B PCO2) differences was studied in bicarbonate-infused and amiloride-treated adrenalectomized rats. U-B PCO2 was significantly reduced by amiloride in bicarbonate-infused control rats. Adrenalectomy further reduced U-B PCO2 in amiloride-treated, bicarbonate-infused rats (from 27.9 ± 1.82 mmHg in sham-operated rats to 21.3 ± 1.58 mmHg in adrenalectomized (ADX) rats) (1 mmHg = 133.322 Pa). Acute administration of corticosterone and 18-hydroxycorticosterone (18-OH-B), but not of aldosterone, caused recovery of U-B PCO2 to the level of sham-operated animals treated with amiloride. Aldosterone did not affect U-B PCO2 in the presence of amiloride (21.9 mmHg ADX group vs. 20.98 mmHg aldosterone group). Results are compatible with aldosterone affecting distal H ion secretion mostly by a sodium and potential difference dependent mechanism, while corticosterone and 18-OH-B should act by other mechanisms (e.g., increased luminal buffer level). |
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