Endothelium-dependent frequency modulation of Ca2+ signalling in individual vascular smooth muscle cells of the rat.
AUTOR(ES)
Kasai, Y
RESUMO
1. We visualized intracellular Ca2+ concentration ([Ca2+]i) changes, using fluo-3 as an indicator, of individual vascular smooth muscle cells and endothelial cells within intact rat tail arteries by confocal microscopy. 2. Using a piezo-driven objective, we focused on endothelial and smooth muscle cell layers alternately to obtain Ca2+ images of their cells. In the presence of 1 microM acetylcholine (ACh), individual endothelial cells responded with intermittent increases in the [Ca2+]i (Ca2+ oscillations). At the same time, the frequency of Ca2+ oscillations in smooth muscle cells induced by electrical stimulation of the perivascular sympathetic nerve was greatly decreased. 3. A [Ca2+]i rise during the oscillations in the endothelial cells propagated in the form of a wave along the long axis of the cells. 4. In the presence of a NO synthase inhibitor, no significant inhibitory effect of ACh on the Ca2+ signalling in the vascular smooth muscle cells was detected, although the Ca2+ oscillations in the endothelial cells persisted. 5. The inhibitory effect of ACh on the frequency of Ca2+ oscillations in the vascular smooth muscle cells was mimicked by 1 microM sodium nitroprusside, a NO donor. 6. These results indicate that Ca2+ waves and oscillations in vascular endothelial cells regulate NO production, which modulates vascular tone by decreasing the frequency of Ca2+ oscillations in smooth muscle cells activated by sympathetic agonists.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1159915Documentos Relacionados
- Some electrical properties of the endothelium-dependent hyperpolarization recorded from rat arterial smooth muscle cells.
- Calcium dependency of the endothelium-dependent hyperpolarization in smooth muscle cells of the rabbit carotid artery.
- Lysolecithins as endothelium-dependent vascular smooth muscle relaxants that differ from endothelium-derived relaxing factor (nitric oxide)
- Lysolecithins as endothelium-dependent vascular smooth muscle relaxants that differ from endothelium-derived relaxing factor (nitric oxide)
- Agonist-dependent Ca2+ and Mn2+ entry dependent on state of filling of Ca2+ stores in aortic smooth muscle cells of the rat.