| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Division of Endocrinology and Diabetology, Department of Internal Medicine (N.L., V.R., M.F.R.), Laboratory of Clinical Chemistry, Department of Pathology (M.F.R.), and Department of Physiology (S.A., N.D.), University Hospital, CH-1211 Geneva 14, Switzerland
Address all correspondence and requests for reprints to: Dr. Michel F. Rossier, Division of Endocrinology and Diabetology, University Hospital, 24 rue Micheli du Crest, CH-1211 Geneva 14, Switzerland. E-mail: michel.rossier{at}medecine.unige.ch.
Angiotensin II and extracellular potassium stimulate aldosterone production in adrenal glomerulosa cells by mobilizing the calcium messenger system. This response requires calcium influx across the plasma membrane, followed by calcium uptake into the mitochondria. It has been proposed that calcium is transported to the mitochondria via the lumen of the endoplasmic reticulum, acting as a kind of intracellular calcium pipeline. This hypothesis has been tested in the present study by measuring intramitochondrial calcium variations in H295R cells with a new fluorescent calcium probe, ratiometric pericam. Calyculin A, a protein phosphatase inhibitor, induced the formation of a large cortical layer of actin filaments, removing the peripheral endoplasmic reticulum away from the plasma membrane and thereby physically uncoupling the calcium channels from the pipeline. The mitochondrial calcium response to potassium was markedly reduced after calyculin treatment, but that of AngII was unaffected. Under the same conditions, potassium-stimulated pregnenolone and aldosterone production was significantly reduced, whereas the steroidogenic response to AngII remained unchanged. The inhibitory action of calyculin A on the responses to potassium was not mediated by a modification of the calcium channel activity and was not accompanied by a reduction of the cytosolic calcium response. It therefore appears that, in H295R cells, the organization of the actin cytoskeleton at the cell periphery influences the steroidogenic action of potassium, but not the response to angiotensin II. The response to potassium is proposed to be dependent on the endoplasmic reticulum-mediated transfer of calcium entering through plasma membrane calcium channels to the mitochondria.
This article has been cited by other articles:
 |
|
 |
|
  S. Lenglet, F. Antigny, L. Vetterli, J.-F. Dufour, and M. F. Rossier Hint2 Is Expressed in the Mitochondria of H295R Cells and Is Involved in Steroidogenesis Endocrinology, November 1, 2008; 149(11): 5461 - 5469. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y.-C. Chen, M. L Nagpal, D. M Stocco, and T. Lin Effects of genistein, resveratrol, and quercetin on steroidogenesis and proliferation of MA-10 mouse Leydig tumor cells J. Endocrinol., March 1, 2007; 192(3): 527 - 537. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. K. Lee and A. Tse Dominant Role of Mitochondria in Calcium Homeostasis of Single Rat Pituitary Corticotropes Endocrinology, November 1, 2005; 146(11): 4985 - 4993. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Gratschev, T. Blom, S. Bjorklund, and K. Tornquist Phosphatase Inhibition Reveals a Calcium Entry Pathway Dependent on Protein Kinase A in Thyroid FRTL-5 Cells: COMPARISON WITH STORE-OPERATED CALCIUM ENTRY J. Biol. Chem., November 26, 2004; 279(48): 49816 - 49824. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Metzeler, A. Agoston, and M. Gratzl An Intrinsic {gamma}-Aminobutyric Acid (GABA)ergic System in the Adrenal Cortex: Findings from Human and Rat Adrenal Glands and the NCI-H295R Cell Line Endocrinology, May 1, 2004; 145(5): 2402 - 2411. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Endocrinology | Endocrine Reviews | J. Clin. End. & Metab. |
| Molecular Endocrinology | Recent Prog. Horm. Res. | All Endocrine Journals |
