Journal article
Cytosolic calcium concentration in resting and stimulated endothelium of excised intact rat aorta
The Journal of physiology, Vol.489(Pt 2), pp.309-317
12/01/1995
DOI: 10.1113/jphysiol.1995.sp021052
PMCID: PMC1156759
PMID: 8847627
Abstract
1. Optical fibres were used to excite and record fluorescence from the lumenal face of rat aorta or tail artery loaded with fura-2. 2. Acetylcholine (ACh) evoked an endothelium-dependent rise in the fura-2 340/380 nm excitation ratio in both vessels. High [K+] or phenylephrine evoked an endothelium-independent rise in ratio in tail artery but failed to increase the ratio in aorta. These observations indicate that fura-2 fluorescence and therefore cytosolic calcium concentration ([Ca2+]i) may be selectively recorded from the endothelium of intact rat aorta. 3. In aortic endothelium, resting [Ca2+]i was 95 +/- 8 nM (n = 44). ACh evoked a monophasic rise in [Ca2+]i which was temporally coincident with a membrane hyperpolarization. 4. ATP in most (22/35) preparations evoked a rise in [Ca2+]i which declined towards resting and was followed by a secondary rise. The biphasic [Ca2+]i responses were accompanied by biphasic electrical responses of initial hyperpolarization followed by depolarization above the resting potential and subsequent restoration towards rest. In the presence of high [K+] or the K+ ionophore valinomycin, ATP did not evoke changes in membrane potential and only monophasic rises in [Ca2+]i were observed. In some (7/35) preparations, ATP evoked oscillations in [Ca2+]i, with membrane potential oscillating in antiphase. 5. These data suggest interplay between [Ca2+]i and membrane potential in the generation of agonist-evoked responses in native endothelium in situ. The observed oscillations in [Ca2+]i imply spatio-temporal synchronization of Ca2+ signalling in large groups of endothelial cells in intact rat aorta.
Details
- Title: Subtitle
- Cytosolic calcium concentration in resting and stimulated endothelium of excised intact rat aorta
- Creators
- Y M Usachev - Physiological Laboratory, University of Cambridge, UKS M Marchenko - Physiological Laboratory, University of Cambridge, UKS O Sage - Physiological Laboratory, University of Cambridge, UK
- Resource Type
- Journal article
- Publication Details
- The Journal of physiology, Vol.489(Pt 2), pp.309-317
- DOI
- 10.1113/jphysiol.1995.sp021052
- PMID
- 8847627
- PMCID
- PMC1156759
- ISSN
- 0022-3751
- eISSN
- 1469-7793
- Language
- English
- Date published
- 12/01/1995
- Academic Unit
- Iowa Neuroscience Institute; Anesthesia; Fraternal Order of Eagles Diabetes Research Center; Neuroscience and Pharmacology
- Record Identifier
- 9984070891002771
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