Back to Search
Start Over
Intracellular cAMP: the 'switch' that triggers on 'spontaneous transient outward currents' generation in freshly isolated myocytes from thoracic aorta
- Source :
- American Journal of Physiology-Cell Physiology. 292:C1502-C1509
- Publication Year :
- 2007
- Publisher :
- American Physiological Society, 2007.
-
Abstract
- Spontaneous transient outward currents (STOCs) have been reported in resistance and small arteries but have not yet been found in thoracic aorta. Do thoracic aorta myocytes possess cellular machinery that generates STOCs? It was found that the majority of aortic myocytes do not generate STOCs. STOCs were generated in 8.7% of freshly isolated aortic myocytes. Myocytes that did not generate STOCs we have called “silent” myocytes and myocytes with STOCs have been called “active.” STOCs recorded in active myocytes were voltage dependent and were inhibited by ryanodine, caffeine, and charybdotoxin. Forskolin was reported to increase STOCs frequency in myocytes isolated from resistance arteries. Forskolin (10 μM) triggered STOCs generation in 35.1% of silent aortic myocytes. In 36.8% percent of silent myocytes, forskolin did not trigger STOCs but increased the amplitude of charybdotoxin-sensitive outward net current to 136.1 ± 8.5% at 0 mV. Membrane-permeable 8BrcAMP triggered STOCs generation in 38.7% of silent myocytes. Forskolin- or 8BrcAMP-triggered STOCs were inhibited by charybdotoxin. 8BrcAMP also increased open probability of BKCa channels in BAPTA-AM-pretreated cells. Our data demonstrate that, in contrast to resistance arteries, STOCs are present just in the minority of myocytes in the thoracic aorta. However, cellular machinery that generates STOCs can be “switched” on by cAMP. Such an inactive cellular mechanism could modulate the contractility of the thoracic aorta in response to physiological demand.
- Subjects :
- Male
medicine.medical_specialty
Patch-Clamp Techniques
Charybdotoxin
Physiology
Intracellular Space
Isolated myocytes
Aorta, Thoracic
In Vitro Techniques
Mice
Potassium Channels, Calcium-Activated
chemistry.chemical_compound
Caffeine
medicine.artery
Internal medicine
Cyclic AMP
medicine
Animals
Thoracic aorta
Myocyte
Muscle Cells
Forskolin
Ryanodine
Colforsin
Cell Biology
Mice, Inbred C57BL
medicine.anatomical_structure
chemistry
Circulatory system
Cardiology
Biophysics
Intracellular
Blood vessel
Artery
Subjects
Details
- ISSN :
- 15221563 and 03636143
- Volume :
- 292
- Database :
- OpenAIRE
- Journal :
- American Journal of Physiology-Cell Physiology
- Accession number :
- edsair.doi.dedup.....dbaedbdda4ac5fc6938949fa7976f8e8