Aldosterone enhances renal calcium reabsorption by two types of channels

Leclerc, Marie; Brunette, Michele G.; Couchourel, Denis
July 2004
Kidney International;Jul2004, Vol. 66 Issue 1, p242
Academic Journal
Aldosterone enhances renal calcium reabsorption by two types of channels. Background. Aldosterone has been known for many years to increase sodium (Na+) reabsorption by the distal nephron. The present in vitro experiments investigated the effect of the hormone on calcium (Ca2+) transport by the luminal membrane of the rabbit nephron, independent of any systemic influence. Methods. Proximal and distal tubules were incubated with either aldosterone or the carrier. The luminal membranes of these tubules were purified, vesiculated, and 45Ca uptake by these vesicles was subsequently measured. Results. Treatment of the distal tubules with 10−8 mol/L aldosterone enhanced both 0.1 and 0.5 mmol/L Ca2+ transport. The hormone action was abolished by tyrosine kinase inhibitors. The presence of Na+ in the medium decreased both Ca2+ uptake and the effect of aldosterone. This hormone action was already significant after a 5-minute incubation, with a half-maximal efficient concentration of approximately 10−10 mol/L. Ca2+ transport by the distal membranes presents a dual kinetics. Aldosterone enhanced the Vmax values of both components of these kinetics. Mibefradil abolished the action of aldosterone on 0.5 mmol/L but not on 0.1 mmol/L Ca2+ uptake, suggesting that the targeted low affinity channel belongs to the T-type, whereas diltiazem prevented the hormone action exclusively at the low Ca2+ concentration (0.1 mmol/L), indicating an effect on a high affinity L-type channel. Conclusion. Aldosterone increases Ca2+ transport by the distal luminal membranes through L- and T-type Ca2+ channels, and this action requires tyrosine kinase activity.


Related Articles

  • Angiotensin II: a candidate for an aldosterone-independent mediator of potassium preservation during volume depletion. Hoover, Robert S. // Kidney International;Feb2011, Vol. 79 Issue 4, p377 

    Two different stimulators of aldosterone secretion, high-potassium diet and low-sodium diet, have disparate effects on potassium secretion in the distal nephron. The mechanism by which the kidney preserves potassium in the face of a high-aldosterone, volume-depleted state has engendered much...

  • Effect of aldosterone on the transepithelial potential difference of the rat distal tubule. Allen, Glen G.; Barratt, Lindsay J. // Kidney International;May1981, Vol. 19 Issue 5, p678 

    Aldosterone, which increases sodium reabsorptjon along the distal nephron of the rat kidney, has not previously been shown to influence the transepithelial potential difference (PD) of this nephron segment in vivo. In contrast, major changes in transepithelial PD have been shown to accompany...

  • In vitro modulation of cyst formation by a novel tyrosine kinase inhibitor. Sweeney, William E.; Futey, Lidia; Frost, Phillip; Avner, Ellis D. // Kidney International;Aug1999, Vol. 56 Issue 2, p406 

    In vitro modulation of cyst formation by a novel tyrosine kinase inhibitor. Background. Recessively transmitted polycystic kidney disease (PKD) in many murine models is characterized by the initial formation of proximal tubular cysts (stage 1), followed by growth and enlargement of renal...

  • ATP Releasing Connexin 30 Hemichannels Mediate Flow-Induced Calcium Signaling in the Collecting Duct. Svenningsen, Per; Burford, James L.; Peti-Peterdi, János // Frontiers in Physiology;Oct2013, Vol. 4, p1 

    ATP in the renal tubular fluid is an important regulator of salt and water reabsorption via purinergic calcium signaling that involves the P2Y2 receptor, ENaC, and AQP2. Recently, we have shown that connexin (Cx) 30 hemichannels are localized to the non-junctional apical membrane of cells in the...

  • Collecting duct-specific gene inactivation of &alphaENaC in the mouse kidney does not impair sodium and potassium balance. Rubera, Isabelle; Loffing, Johannes; Palmer, Lawrence G.; Frindt, Gustavo; Fowler-Jaeger, Nicole; Sauter, Daniel; Carroll, Tom; McMahon, Andrew; Hummler, Edith; Rossier, Bernard C. // Journal of Clinical Investigation;Aug2003, Vol. 112 Issue 4, p554 

    Examines the consequence of inactivating epithelial sodium channel α subunit in collecting duct. Functions of aldosterone; Composition of aldosterone-sensitive distal nephron; Effect of low-sodium diet and aldosterone infusion on sodium channels.

  • Glucocorticords enhance the expression of the basolateral Na[sup+]:HCO[sub3][sup-] cotransporter in renal proximal tubules. Ali, Raza; Amlal, Hassane; Burnham, Charles E.; Soleimani, Manoocher // Kidney International;Mar2000, Vol. 57 Issue 3, p1063 

    Examines the effect of adrenal steroids on basolateral Na[sup +]:HCO[sub 3][sup -] cotransporter (NBC) and Na[sup +]/H[sup +] antiporter (HE-3) expression and activity in rat renal proximal tubules. Increase of cortical NBC-1 messenger RNA expression; Enhancement of NBC and NHE-3 activities by...

  • Long-term effects of vasopressin on the subcellular localization of ENaC in the renal collecting system. Sauter, D.; Fernandes, S.; Goncalves-Mendes, N.; Boulkroun, S.; Bankir, L.; Loffing, J.; Bouby, N. // Kidney International;Mar2006, Vol. 69 Issue 6, p1024 

    Previous studies revealed that chronic (days) vasopressin treatment stimulates amiloride-sensitive sodium transport in isolated renal cortical collecting ducts and increases the abundance of beta- and gamma-subunits of the epithelial sodium channel (ENaC) in the kidney. The aim of the present...

  • H+ transport by the aldosterone-deficient rat distal nephron. Kornandakieti, Chaleomsri; Tannen, Richard L. // Kidney International;Apr1984, Vol. 25 Issue 4, p629 

    The effect of aldosterone on distal nephron acidification was investigated by comparing isolated perfused kidneys from adrenalectomized rats treated for 3 to 5 days with dexamethasone alone (10 mu;g/day i.p.) and from rats given in addition a physiologic dose of d-aldosterone (10 mu;g/day in oil...

  • Interactive effects of angiotensin II on renal hemodynamics and tubular reabsorptive function. Mitchell, Kenneth D.; Navar, L. Gabriel // Kidney International Supplement;Nov1990, Issue 30, pS-69 

    This article focuses on the interactive effects of angiotensin II on renal hemodynamics and tubular reabsorptive function. In addition to its indirect effects mediated at the distal nephron level by the sodium retaining mineralocorticoid, aldosterone, angiotensin II directly influences renal...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics