Abstract
Local increases in intracellular calcium ion concentration ([Ca2+](i)) resulting from activation of the ryanodine-sensitive calcium-release channel in the sarcoplasmic reticulum (SR) of smooth muscle cause arterial dilation. Ryanodine-sensitive, spontaneous local increases in [Ca2+](i) (Ca2+ sparks) from the SR were observed just under the surface membrane of single smooth muscle cells from myogenic cerebral arteries. Ryanodine and thapsigargin inhibited Ca2+ sparks and Ca2+-dependent potassium (K(Ca)) currents, suggesting that Ca2+ sparks activate K(Ca) channels. Furthermore, K(Ca) channels activated by Ca2+ sparks appeared to hyperpolarize and dilate pressurized myogenic arteries because ryanodine and thapsigargin depolarized and constricted these arteries to an extent similar to that produced by blockers of K(Ca) channels. Ca2+ sparks indirectly cause vasodilation through activation of K(Ca) channels, but have little direct effect on spatially averaged [Ca2+](i), which regulates contraction.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 633-637 |
| Number of pages | 5 |
| Journal | Science |
| Volume | 270 |
| Issue number | 5236 |
| State | Published - Oct 27 1995 |
| Externally published | Yes |
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Relaxation of arterial smooth muscle by calcium sparks. / Nelson, M. T.; Cheng, H.; Rubart, M.; Santana, Luis Fernando; Bonev, A. D.; Knot, H. J.; Lederer, W. J.
In: Science, Vol. 270, No. 5236, 27.10.1995, p. 633-637.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Relaxation of arterial smooth muscle by calcium sparks
AU - Nelson, M. T.
AU - Cheng, H.
AU - Rubart, M.
AU - Santana, Luis Fernando
AU - Bonev, A. D.
AU - Knot, H. J.
AU - Lederer, W. J.
PY - 1995/10/27
Y1 - 1995/10/27
N2 - Local increases in intracellular calcium ion concentration ([Ca2+](i)) resulting from activation of the ryanodine-sensitive calcium-release channel in the sarcoplasmic reticulum (SR) of smooth muscle cause arterial dilation. Ryanodine-sensitive, spontaneous local increases in [Ca2+](i) (Ca2+ sparks) from the SR were observed just under the surface membrane of single smooth muscle cells from myogenic cerebral arteries. Ryanodine and thapsigargin inhibited Ca2+ sparks and Ca2+-dependent potassium (K(Ca)) currents, suggesting that Ca2+ sparks activate K(Ca) channels. Furthermore, K(Ca) channels activated by Ca2+ sparks appeared to hyperpolarize and dilate pressurized myogenic arteries because ryanodine and thapsigargin depolarized and constricted these arteries to an extent similar to that produced by blockers of K(Ca) channels. Ca2+ sparks indirectly cause vasodilation through activation of K(Ca) channels, but have little direct effect on spatially averaged [Ca2+](i), which regulates contraction.
AB - Local increases in intracellular calcium ion concentration ([Ca2+](i)) resulting from activation of the ryanodine-sensitive calcium-release channel in the sarcoplasmic reticulum (SR) of smooth muscle cause arterial dilation. Ryanodine-sensitive, spontaneous local increases in [Ca2+](i) (Ca2+ sparks) from the SR were observed just under the surface membrane of single smooth muscle cells from myogenic cerebral arteries. Ryanodine and thapsigargin inhibited Ca2+ sparks and Ca2+-dependent potassium (K(Ca)) currents, suggesting that Ca2+ sparks activate K(Ca) channels. Furthermore, K(Ca) channels activated by Ca2+ sparks appeared to hyperpolarize and dilate pressurized myogenic arteries because ryanodine and thapsigargin depolarized and constricted these arteries to an extent similar to that produced by blockers of K(Ca) channels. Ca2+ sparks indirectly cause vasodilation through activation of K(Ca) channels, but have little direct effect on spatially averaged [Ca2+](i), which regulates contraction.
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M3 - Article
C2 - 7570021
AN - SCOPUS:0028807878
VL - 270
SP - 633
EP - 637
JO - Science
JF - Science
SN - 0036-8075
IS - 5236
ER -