Local anesthetic inhibition of G protein-coupled receptor signaling by interference with Galpha(q) protein function.
Although local anesthetics are considered primarily Na(+) channel blockers, previous studies suggest a common intracellular site of action on different G protein-coupled receptors. In the present study, we characterized this site for the LPA, m1 muscarinic, and trypsin receptor. Xenopus laevis oocytes expressing endogenous LPA and trypsin or recombinant m1 receptors were two-electrode voltage clamped. We studied LPA inhibition in the presence of ropivacaine stereoisomers to determine whether LA act on a protein site. Ropivacaine inhibited LPA signaling in a stereoselective and noncompetitive manner, suggesting a protein interaction. Antisense injection was used to characterize G protein alpha-subunits involved in mediation of LPA, m1, trypsin, and angiotensin(1A) receptor signaling. Lidocaine and its analog QX314 were injected into oocytes expressing these receptors to examine a potential role for specific G protein alpha-subunits as targets for LA. Galpha(q) was shown to be among the primary G protein subunits mediating the LPA, m1, and trypsin receptor signaling, all of which were inhibited to a similar degree by intracellular injected QX314 (424 x 10(-6) M). Since the angiotensin(1A) receptor, previously shown not to be affected by LA, was found not to signal via Galpha(q), but via Galpha(o) and Galpha(14), the intracellular effect of LA most likely takes place at the Galpha(q)-subunit.
Hollmann
M W
MW
Department of Anesthesiology and Pain Management, University Hospital Maastricht, The Netherlands.
Wieczorek
K S
KS
Berger
A
A
Durieux
M E
ME
D000577:Amides / Q000494:pharmacology; D000779:Anesthetics, Local / Q000494:pharmacology*; D000818:Animals; D001665:Binding Sites; D004347:Drug Interactions; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D020962:Heterotrimeric GTP-Binding Proteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D008012:Lidocaine / Q000031:analogs & derivatives* / Q000494:pharmacology; D008246:Lysophospholipids / Q000378:metabolism; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism; D044140:Receptor, Angiotensin, Type 1; D043643:Receptor, Muscarinic M1; D011945:Receptors, Angiotensin / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000037:antagonists & inhibitors; D043562:Receptors, G-Protein-Coupled; D049368:Receptors, Lysophosphatidic Acid; D011976:Receptors, Muscarinic / Q000378:metabolism; D000077212:Ropivacaine; D015398:Signal Transduction / Q000187:drug effects*; D014357:Trypsin / Q000378:metabolism; D014982:Xenopus laevis
D000577:Amides; D000779:Anesthetics, Local; D008246:Lysophospholipids; D016376:Oligonucleotides, Antisense; D044140:Receptor, Angiotensin, Type 1; D043643:Receptor, Muscarinic M1; D011945:Receptors, Angiotensin; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; D049368:Receptors, Lysophosphatidic Acid; D011976:Receptors, Muscarinic; C012647:QX-314; D000077212:Ropivacaine; D008012:Lidocaine; D014357:Trypsin; C119109:GNA14 protein, human; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D020962:Heterotrimeric GTP-Binding Proteins