Medical College of Wisconsin
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Angiotensin II mediates a sustained rise in nuclear and cytoplasmic calcium via multiple receptor subtypes. Am J Physiol 1995 Aug;269(2 Pt 2):H565-70 PMID: 7653620

Abstract

Alterations in nuclear calcium levels in response to angiotensin II (ANG II) may play an important role in the trophic actions of ANG II. This study utilized confocal microscopy and nuclear staining to test the hypothesis that both nuclear and cytoplasmic calcium levels are altered in response to ANG II stimulation of freshly dissociated aortic smooth muscle cells. Cells were loaded with the calcium indicator fluo 3 acetoxymethyl ester, and the calcium response to ANG II stimulation was analyzed over time with a laser-scanning confocal microscope. Additionally, the ratiometric calcium indicator fura 2 acetoxymethyl ester and conventional fluorescence microscopy were used to verify these observations. Results show that basal nuclear calcium exceeds cytoplasmic calcium in these cells. Stimulation by ANG II induces a sustained rise (separate from the rapid transient) in both nuclear and cytoplasmic calcium in excess of 20 min in duration. This rise was blockable by either the AT1 receptor antagonist DuP-753 or by the AT2 antagonist PD-123319. Thus ANG II stimulates a sustained rise in nuclear calcium by a mechanism that necessitates activation of both AT1 and AT2 receptors.

Author List

Munzenmaier DH, Greene AS

Author

Andrew S. Greene PhD Interim Vice Chair, Chief, Professor in the Biomedical Engineering department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Angiotensin II
Aniline Compounds
Animals
Calcium
Cell Nucleus
Cytoplasm
Fluorescent Dyes
Fura-2
Microscopy, Confocal
Microscopy, Fluorescence
Muscle, Smooth, Vascular
Rats
Rats, Sprague-Dawley
Receptors, Angiotensin
Xanthenes



View this publication's entry at the Pubmed website PMID: 7653620
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