Membrane currents evoked by histamine in rabbit basilar artery

Masahiro Kamouchi, Rika Ogata, Masatoshi Fujishima, Yushi Ito, Kenji Kitamura

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

The membrane current evoked by histamine in isolated smooth muscle cells from rabbit basilar artery was investigated using the perforated-patch technique. When 10 μM histamine was applied in the bath at a holding potential of 60 mV, an inward current (79.2 ± 55.8 pA) was transiently activated. An outward current was additionally evoked by 10 μM histamine when the membrane was held at -40 mV or less negative potentials. The outward but not the inward current was completely blocked by 100 nM charybdotoxin. A higher concentration of histamine (30 μM) failed to produce the inward current (3.4 ± 4.8 pA) when Cl- concentration in the pipette was reduced. The apparent reversal potential of the inward current induced by histamine in physiological salt solution, in high-tetraethylammonium (TEA+) solution (bath), or in low-Cl- solution (pipette) was -6.3 ± 4.4, -7.5 ± 4.9, or - 45.8 ± 8.5 mV, respectively. Niflumic acid (100 μM) reversibly blocked the inward current, which was also blocked by 10 μM pyrilamine but not by 10 μM cimetidine. When histamine was continuously applied in the bath, spontaneous transient inward currents were generated. Removal of external Ca2+ or addition of 1 μM nicardipine or 2 mM caffeine reduced the amplitude of the histamine-induced inward current. These results suggest that histamine induces an inward current via H1 receptors at the resting membrane potential, possibly due to activation of Cl- currents. The Cl- inward current might be generated by elevation of intracellular Ca2+ via histamine receptors. The inward current may also contribute to control of the Ca2+ influx via a change in the membrane potential.

Original languageEnglish
Pages (from-to)H638-H647
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Volume272
Issue number2 41-2
DOIs
Publication statusPublished - Feb 1997

All Science Journal Classification (ASJC) codes

  • Physiology
  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

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