[Fast nongenomic aldosterone effect on the kinetics of intracellular sodium and cell volume in the cortical part of collecting ducts of the rat kidney].
The fast nongenomic aldosterone effect on intracellular sodium ([Na+]i) and cell volume was studied by the fluorescent microscopy in isolated cortical part of collecting duct of the rat kidney (CCD). It was shown that aldosterone (10 nM) raised [Na+]i in hyposodium outer medium (14 mM). The rate of [Na+]i changes in response to external sodium shift (137-14 mM) twice as low in the presence of aldosterone (p < 0.05). Corticosterone (100 nM) was unable to simulate aldosterone effect. Similarly to sodium channel blocker amiloride (10(-5) M), protein kinase C (PKC) inhibitor RO-31-8220 (10(-7) M) abolished aldosterone effect. Aldosterone (10 nM) significantly decreased the amplitude and increased the characteristic time of the cell volume restoration in hypotonic medium of the rat principle cells (p < 0.001). Corticosterone (50 nM) was also unable to reproduce aldosterone effect. Amiloride (10(-5) M) did not significantly influence either the amplitude or the characteristic time of cell volume restoration during hypoosmotic challenge (p > 0.05). For the first time the specificity and important role of Ca(2+)-dependent kinase in the nongenomic aldosterone effects on ENaC activity and cell volume regulation in rat CCD were demonstrated.
N S
NS
Logvinenko
E I
EI
Solenov
L N
LN
Ivanova
D000450:Aldosterone / Q000494:pharmacology*; D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D048429:Cell Size / Q000187:drug effects*; D053503:Epithelial Sodium Channels / Q000502:physiology*; D066298:In Vitro Techniques; D007211:Indoles / Q000494:pharmacology; D007685:Kidney Tubules, Collecting / Q000187:drug effects* / Q000502:physiology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism; D051381:Rats; D012964:Sodium / Q000378:metabolism*
D053503:Epithelial Sodium Channels; D007211:Indoles; D000450:Aldosterone; D000584:Amiloride; D012964:Sodium; D011493:Protein Kinase C; C064758:Ro 31-8220