Abstract
The sulfur-containing amino acid homocysteic acid (HCA) is present in and released from nervous tissue, exerting excitatory effects on neurons by predominantly activating NMDA receptors. It is interesting that HCA appears to be exclusively localized in glial cells, not in neurons. This profile of glial localization and excitatory action on neurons has led to the hypothesis that HCA could participate in intercellular communication in the brain as a "gliotransmitter." To test this hypothesis further, we searched for specific, receptor-mediated stimuli that could induce release of HCA from cultured astrocytes. For this reason we tested the effect of noradrenaline and vasoactive intestinal peptide, two transmitters known to interact with specific receptors on astrocytes, on the release of HCA from these cells. Noradrenaline and the beta-adrenergic agonist isoproterenol induced an efflux of HCA from astrocyte cultures. Further stressing the beta-adrenergic mediation of this effect is the blockade by atenolol of the HCA release evoked by isoproterenol. The stimulation of HCA release from astrocytes was not observed with the alpha-noradrenergic agonist methoxamine and with vasoactive intestinal peptide. These results taken together fu...Continue Reading
Citations
Mar 22, 2005·Glia·Guowei HuangJohn X Wilson
Feb 25, 2006·The Journal of Comparative Neurology·Yasmin NasserKeith A Sharkey
Jan 18, 2008·Journal of Human Hypertension·A PoduriM Khullar
Sep 5, 2015·Journal of Neurochemistry·Ann MassieJan Lewerenz
May 26, 1999·Glia·V MaienscheinH Zimmermann
Aug 5, 2009·Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences·S Kasparov, A G Teschemacher
Feb 9, 2012·ASN Neuro·Robert ZorecVladimir Parpura
Apr 27, 2001·Journal of Cerebral Blood Flow and Metabolism : Official Journal of the International Society of Cerebral Blood Flow and Metabolism·S ZerarkaP J Magistretti
Mar 22, 2003·The Journal of Pharmacology and Experimental Therapeutics·Qi ShiBryan L Roth
Feb 3, 2009·Journal of Neurochemistry·Suzie LavoieKim Q Do
Jan 20, 2018·Glia·Sigrid Ottestad-HansenNiels Christian Danbolt
Nov 29, 2002·The Journal of Physiology·Johannes Brockhaus, Joachim W Deitmer
Jun 7, 2012·Antioxidants & Redox Signaling·Jan LewerenzPamela Maher
Mar 29, 2001·Pain·Y M Ulrich-LaiK M Hargreaves
Dec 17, 2020·Frontiers in Neurology·Quirijn P VerhoogErwin A van Vliet
Jul 6, 2000·Progress in Neurobiology·G Carmignoto
Aug 23, 2005·Progress in Neuro-psychopharmacology & Biological Psychiatry·Aron M Troen
Jul 12, 2011·Medical Hypotheses·W N Marsden