Angiotensin II inhibits calcium and M current channels in rat sympathetic neurons via G proteins

Mark S. Shapiro, Lonnie P. Wollmuth, Bertil Hille

Research output: Contribution to journalArticlepeer-review

122 Scopus citations

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 languageEnglish (US)
Pages (from-to)1319-1329
Number of pages11
JournalNeuron
Volume12
Issue number6
DOIs
StatePublished - Jun 1994
Externally publishedYes

ASJC Scopus subject areas

  • Neuroscience(all)

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