This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (8) Citing Articles via Google Scholar Google Scholar Articles by Brosnan, R. Articles by Sonner, J. M. Search for Related Content PubMed PubMed Citation Articles by Brosnan, R. Articles by Sonner, J. M. Related Collections Mechanisms Pharmacology

---

ANESTHETIC PHARMACOLOGY

Chirality in Anesthesia II: Stereoselective Modulation of Ion Channel Function by Secondary Alcohol Enantiomers

Robert Brosnan, DVM, PhD^*, Diane Gong, PharmD, Joseph Cotten, MD, PhD, Bharat Keshavaprasad, MD, C. Spencer Yost, MD, Edmond I. Eger, II, MD, and James M. Sonner, MD

From the *Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis; The University of Texas at Austin, Waggoner Center for Alcohol and Addiction Research; The Department of Anesthesia and Critical Care Massachusetts General Hospital and The Department of Anesthesia and Perioperative Care, University of California, San Francisco, California.

Address correspondence to James M. Sonner, MD, Department of Anesthesia, S-455i, University of California, San Francisco, CA 94143-0464. Address e-mail to sonnerj{at}anesthesia.ucsf.edu.

Chirality has been proposed as a means for distinguishing relevant from irrelevant molecular targets of action, but the sensitivity and specificity of this test is unknown for volatile anesthetics. We applied enantiomers of two chiral anesthetic alcohols (2-butanol and 2-pentanol) that are enantioselective for the minimum alveolar concentration (MAC) preventing movement in 50% of animals and one (2-hexanol) that was not to frog oocytes. Each oocyte expressed one of three anesthetic-sensitive ion channels: a Twik-related-spinal cord K⁺ (TRESK) channel, a -amino butyric acid type A (GABA_A) receptor and an N-methyl-d-aspartate (NMDA) receptor. Using voltage-clamp techniques, we found that 2-butanol was not enantioselective for any channel (e.g., 16 mM 2-butanol R(–) and S(–) enantiomers decreased current through an NMDA receptors by 44% ± 3% [mean ± se] and 37% ± 4%, respectively); 2-pentanol was enantioselective for one channel (the GABA_A receptor, the enantiomers increasing current by 277% ± 20% and 141% ± 30%); 2-hexanol was enantioselective for both GABA_A and NMDA receptors (e.g., decreasing current through the NMDA receptor by 19% ± 3% and 43% ± 5%). We calculated the sensitivity and specificity of chirality as a test of anesthetic relevance under two scenarios: 1) all three channels were relevant mediators of MAC and 2) no channel was a mediator of MAC. These sensitivities and specificities were poor because there is no consistent correspondence between receptor and whole animal results. We recommend that enantioselectivity not be used as a test of relevance for inhaled anesthetic targets.

This article has been cited by other articles:

				E. I. Eger II, D. E. Raines, S. L. Shafer, H. C. Hemmings Jr, and J. M. Sonner Is a New Paradigm Needed to Explain How Inhaled Anesthetics Produce Immobility? Anesth. Analg., September 1, 2008; 107(3): 832 - 848. [Abstract] [Full Text] [PDF]

				J. M. Sonner A Hypothesis on the Origin and Evolution of the Response to Inhaled Anesthetics Anesth. Analg., September 1, 2008; 107(3): 849 - 854. [Abstract] [Full Text] [PDF]

				L. Yang and J. M. Sonner Anesthetic-Like Modulation of Receptor Function by Surfactants: A Test of the Interfacial Theory of Anesthesia Anesth. Analg., September 1, 2008; 107(3): 868 - 874. [Abstract] [Full Text] [PDF]

				L. Yang and J. M. Sonner The Anesthetic-Like Effects of Diverse Compounds on Wild-Type and Mutant {gamma}-Aminobutyric Acid Type A and Glycine Receptors Anesth. Analg., March 1, 2008; 106(3): 838 - 845. [Abstract] [Full Text] [PDF]

				L. Yang, J. Zhao, P. S. Milutinovic, R. J. Brosnan, E. I. Eger II, and J. M. Sonner Anesthetic Properties of the Ketone Bodies {beta}-Hydroxybutyric Acid and Acetone Anesth. Analg., September 1, 2007; 105(3): 673 - 679. [Abstract] [Full Text] [PDF]

				P. S. Milutinovic, L. Yang, R. S. Cantor, E. I. Eger II, and J. M. Sonner Anesthetic-Like Modulation of a {gamma}-Aminobutyric Acid Type A, Strychnine-Sensitive Glycine, and N-Methyl-d-Aspartate Receptors by Coreleased Neurotransmitters Anesth. Analg., August 1, 2007; 105(2): 386 - 392. [Abstract] [Full Text] [PDF]

				R. J. Brosnan, L. Yang, P. S. Milutinovic, J. Zhao, M. J. Laster, E. I. Eger II, and J. M. Sonner Ammonia Has Anesthetic Properties Anesth. Analg., June 1, 2007; 104(6): 1430 - 1433. [Abstract] [Full Text] [PDF]