title: Inhibition of the Na,K-ATPase of canine renal medulla by several local anesthetics.
abstract: The ATPase activity of Na,K-ATPase-enriched membranes from canine renal medulla was determined in the absence of local anesthetic and in the presence of procaine, chloroprocaine, bupivacaine, mepivacaine, lidocaine, and two quaternary derivatives of lidocaine (QX-222 and QX-314) at 37( composite function)C. Chloroprocaine (IC(50)= 13 mM) had slightly greater potency than procaine (IC(50)= 17.7 mM). Bupivacaine (IC(50)= 6.7 mM) was more potent than its congener mepivacaine (IC(50)> 10 mM, the solubility limit). QX-222 (IC(50)> 600 mM) and QX-314 (IC(50)= 132 mM) had less potency than lidocaine (IC(50)= 30.4 mM). This study supports the interpretation that the uncharged forms of local anesthetics are much more potent inhibitors of Na,K-ATPase activity than the cationic forms.
authors.affiliation: Department of Molecular Physiology & Biological Physics, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA. kutchai@virginia.edu
authors.forename: H
authors.initials: H
authors.lastname: Kutchai
authors.forename: L M
authors.initials: LM
authors.lastname: Geddis
mesh_terms: D000577:Amides / Q000737:chemistry / Q000494:pharmacology; D000779:Anesthetics, Local / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D000818:Animals; D002045:Bupivacaine / Q000737:chemistry / Q000494:pharmacology; D004285:Dogs; D007679:Kidney Medulla / Q000187:drug effects* / Q000201:enzymology*; D008012:Lidocaine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D008619:Mepivacaine / Q000494:pharmacology; D011343:Procaine / Q000031:analogs & derivatives / Q000737:chemistry / Q000494:pharmacology; D011485:Protein Binding; D000077212:Ropivacaine; D015222:Sodium Channels / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors* / Q000378:metabolism
chemical_list: D000577:Amides; D000779:Anesthetics, Local; D015222:Sodium Channels; C006072:QX-222; C012647:QX-314; D011343:Procaine; C004616:chloroprocaine; D000077212:Ropivacaine; D008012:Lidocaine; D008619:Mepivacaine; D000254:Sodium-Potassium-Exchanging ATPase; D002045:Bupivacaine