Academic Journal
Elementary purinergic Ca2+ transients evoked by nerve stimulation in rat urinary bladder smooth muscle
| العنوان: | Elementary purinergic Ca2+ transients evoked by nerve stimulation in rat urinary bladder smooth muscle |
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| المؤلفون: | Heppner, Thomas J., Bonev, Adrian D., Nelson, Mark T. |
| المصدر: | Heppner , T J , Bonev , A D & Nelson , M T 2005 , ' Elementary purinergic Ca2+ transients evoked by nerve stimulation in rat urinary bladder smooth muscle ' , Journal of Physiology , vol. 564 , no. 1 , pp. 201-212 . https://doi.org/10.1113/jphysiol.2004.077826 |
| سنة النشر: | 2005 |
| المجموعة: | The University of Manchester: Research Explorer - Publications |
| مصطلحات موضوعية: | Animals, drug effects: Calcium Signaling, pharmacology: Diltiazem, methods: Electric Stimulation, Male, drug effects: Muscle, Smooth, Rats, physiology: Receptors, Purinergic P2, drug effects: Synaptic Transmission, drug effects: Urinary Bladder |
| الوصف: | The translation of nerve transmission to Ca2+ signals in urinary bladder smooth muscle (UBSM) is incompletely understood. Thus, we sought to characterize Ca2+ signals in strips of UBSM loaded with the Ca2+-sensitive fluorescent dye, fluo-4, using laser scanning confocal microscopy. Two types of Ca2+ signals occurred spontaneously and could be evoked with field stimulation: large, rapid, global Ca2+ transients termed 'global Ca2+ flashes', and much smaller, localized Ca2+ transients. Global Ca2+ flashes were inhibited by the L-type voltage-dependent Ca2+ channel (VDCC) inhibitor, diltiazem and with P2X receptor blockade. Simultaneous intracellular recordings and Ca2+ measurements indicated that these events are caused by Ca2+ influx through VDCCs during action potentials. Small, local Ca2+ transients occurred spontaneously, and their frequency could be elevated with field stimulation. Atropine, an inhibitor of muscarinic receptors, did not affect these local Ca2+ transients. However, the desensitizing P2X receptor agonist α,β-methylene ATP, and the purinergic antagonist, suramin, effectively inhibited the local Ca2+ transients. The frequency of these 'purinergic Ca2+ transients' was increased about 7-fold by a 10 s stimulus train (1 Hz). The amplitude, duration at one-half amplitude and the spatial spread of the evoked purinergic Ca2+ transients were F/Fo = 2.4 ± 0.13, 111.7 ± 9.3 ms and 14.0 ± 1.0 μm2, respectively. Tetrodotoxin inhibited evoked purinergic Ca2+ transients, indicating that they were dependent on nerve fibre activation. Purinergic Ca2+ transients were not dependent on VDCC activity. Neither 2-APB, an inhibitor of inositol 1,4,5-triphosphate (Ins(1,4,5)P3) (IP3)-induced Ca2+ release, nor ryanodine inhibited the purinergic Ca2+ transients. We have identified two novel Ca2+ signals in rat UBSM. Large, rapid, global Ca2+ flashes that represent Ca2+ influx through VDCCs during action potentials, and local, purinergic Ca2+ transients that represent Ca2+ entry through P2X receptors. Our results indicate ... |
| نوع الوثيقة: | article in journal/newspaper |
| اللغة: | English |
| DOI: | 10.1113/jphysiol.2004.077826 |
| الاتاحة: | https://research.manchester.ac.uk/en/publications/9a52407f-82e8-44a1-a559-942f2e3c2c3b https://doi.org/10.1113/jphysiol.2004.077826 |
| Rights: | info:eu-repo/semantics/closedAccess |
| رقم الانضمام: | edsbas.1B170B94 |
| قاعدة البيانات: | BASE |
| DOI: | 10.1113/jphysiol.2004.077826 |
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