Abstract
We characterized inhibition of N-type Ca2+ and M current K+ channels in rat superior cervical ganglion neurons by angiotensin II (angioII) using the patch clamp. Of 120 neurons, 97 showed inhibition of ICa (mean 32%), which was slow in onset and very slow to reverse under whole-cell recording conditions. This inhibition was blocked by the AT1 receptor antagonist losartan, attenuated by inclusion of 2 mM GDP-β-S in the pipette, mostly pertussis toxin insensitive, half-sensitive to N-ethylmaleimide, and wholly voltage independent. With 20 mM instead of 0.1 mM BAPTA in the pipette, the inhibition was strongly attenuated; however, we detected no angioII-induced [Ca2+]i signal using the fluorescent indicator indo-1. IBa from cell-attached patches was reduced by bath-applied angioll (mean 33%), suggesting use of a diffusible cytoplasmic messenger. M currents were inhibited by angioll in 8 of 11 neurons (mean 50%) cultured overnight. Hence, a second agonist, angioll, may share the slow, second messenger-utilizing, pertussis toxin-insensitive signaling pathway used by muscarinic agonists.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1319-1329 |
| Number of pages | 11 |
| Journal | Neuron |
| Volume | 12 |
| Issue number | 6 |
| DOIs | |
| State | Published - 1994 |
| Externally published | Yes |
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Angiotensin II inhibits calcium and M current channels in rat sympathetic neurons via G proteins. / Shapiro, Mark S; Wollmuth, Lonnie P.; Hille, Bertil.
In: Neuron, Vol. 12, No. 6, 1994, p. 1319-1329.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Angiotensin II inhibits calcium and M current channels in rat sympathetic neurons via G proteins
AU - Shapiro, Mark S
AU - Wollmuth, Lonnie P.
AU - Hille, Bertil
PY - 1994
Y1 - 1994
N2 - We characterized inhibition of N-type Ca2+ and M current K+ channels in rat superior cervical ganglion neurons by angiotensin II (angioII) using the patch clamp. Of 120 neurons, 97 showed inhibition of ICa (mean 32%), which was slow in onset and very slow to reverse under whole-cell recording conditions. This inhibition was blocked by the AT1 receptor antagonist losartan, attenuated by inclusion of 2 mM GDP-β-S in the pipette, mostly pertussis toxin insensitive, half-sensitive to N-ethylmaleimide, and wholly voltage independent. With 20 mM instead of 0.1 mM BAPTA in the pipette, the inhibition was strongly attenuated; however, we detected no angioII-induced [Ca2+]i signal using the fluorescent indicator indo-1. IBa from cell-attached patches was reduced by bath-applied angioll (mean 33%), suggesting use of a diffusible cytoplasmic messenger. M currents were inhibited by angioll in 8 of 11 neurons (mean 50%) cultured overnight. Hence, a second agonist, angioll, may share the slow, second messenger-utilizing, pertussis toxin-insensitive signaling pathway used by muscarinic agonists.
AB - We characterized inhibition of N-type Ca2+ and M current K+ channels in rat superior cervical ganglion neurons by angiotensin II (angioII) using the patch clamp. Of 120 neurons, 97 showed inhibition of ICa (mean 32%), which was slow in onset and very slow to reverse under whole-cell recording conditions. This inhibition was blocked by the AT1 receptor antagonist losartan, attenuated by inclusion of 2 mM GDP-β-S in the pipette, mostly pertussis toxin insensitive, half-sensitive to N-ethylmaleimide, and wholly voltage independent. With 20 mM instead of 0.1 mM BAPTA in the pipette, the inhibition was strongly attenuated; however, we detected no angioII-induced [Ca2+]i signal using the fluorescent indicator indo-1. IBa from cell-attached patches was reduced by bath-applied angioll (mean 33%), suggesting use of a diffusible cytoplasmic messenger. M currents were inhibited by angioll in 8 of 11 neurons (mean 50%) cultured overnight. Hence, a second agonist, angioll, may share the slow, second messenger-utilizing, pertussis toxin-insensitive signaling pathway used by muscarinic agonists.
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UR - http://www.scopus.com/inward/citedby.url?scp=0028283042&partnerID=8YFLogxK
U2 - 10.1016/0896-6273(94)90447-2
DO - 10.1016/0896-6273(94)90447-2
M3 - Article
C2 - 7516687
AN - SCOPUS:0028283042
VL - 12
SP - 1319
EP - 1329
JO - Neuron
JF - Neuron
SN - 0896-6273
IS - 6
ER -