TY - JOUR
T1 - Arachidonic acid-induced channel- and carrier-type ion transport across planar bilayer lipid membranes
AU - Hirano, Ayumi
AU - Namatame, Yuko
AU - Wakaizumi, Eiichi
AU - Matsuno, Yuka
AU - Sugawara, Masao
PY - 2003/2/1
Y1 - 2003/2/1
N2 - Transmembrane ion transport by arachidonic acid (AA) through bilayer lipid membranes (BLMs) was investigated by means of electrochemical measurements to provide a basis for designing a sensor membrane. We found that AA induces a channel-type current, in addition to a carrier-type current, across planar BLMs. A linear relation between the logarithmic value of the AA concentration and the current responses (given as integrated currents) was observed for a carrier-type current, while a sigmoid relation was found for a channel-type current. Although AA transports Na+, Ca2+ and Mg2+ and exhibits ion selectivity between Na+ and Mg2+ for the carrier-type current, ion transport for the channel-type current was non-selective. It was found that ion transport via the channel mechanism occurs frequently for AA, while channel-type currents were only occasionally observed for γ-linolenic acid and prostaglandin D2. No channel-type currents were induced by other fatty acids (oleic, linoleic, stearic, myristic, eicosapentanoic and docosahexanoic acids) and metabolites of AA (12-HETE and 5-HETE). The carrier-type ion transport occurs selectively to these compounds if the concentration is below 1.0 μM. These results suggest that AA selectively facilitates an ion flux through the BLMs, generating channel-type and/or carrier-type currents, which can be used as a measure of the AA concentration.
AB - Transmembrane ion transport by arachidonic acid (AA) through bilayer lipid membranes (BLMs) was investigated by means of electrochemical measurements to provide a basis for designing a sensor membrane. We found that AA induces a channel-type current, in addition to a carrier-type current, across planar BLMs. A linear relation between the logarithmic value of the AA concentration and the current responses (given as integrated currents) was observed for a carrier-type current, while a sigmoid relation was found for a channel-type current. Although AA transports Na+, Ca2+ and Mg2+ and exhibits ion selectivity between Na+ and Mg2+ for the carrier-type current, ion transport for the channel-type current was non-selective. It was found that ion transport via the channel mechanism occurs frequently for AA, while channel-type currents were only occasionally observed for γ-linolenic acid and prostaglandin D2. No channel-type currents were induced by other fatty acids (oleic, linoleic, stearic, myristic, eicosapentanoic and docosahexanoic acids) and metabolites of AA (12-HETE and 5-HETE). The carrier-type ion transport occurs selectively to these compounds if the concentration is below 1.0 μM. These results suggest that AA selectively facilitates an ion flux through the BLMs, generating channel-type and/or carrier-type currents, which can be used as a measure of the AA concentration.
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U2 - 10.2116/analsci.19.191
DO - 10.2116/analsci.19.191
M3 - Article
C2 - 12608744
AN - SCOPUS:0037327705
SN - 0910-6340
VL - 19
SP - 191
EP - 197
JO - Analytical Sciences
JF - Analytical Sciences
IS - 2
ER -