Halothane inhibits spontaneous calcium oscillations via adenosine A1 receptors.
Primary rat hippocampal neurons show spontaneous [Ca(2+)(i)]-oscillations in Mg(2+)-free medium, which depend on excitatory signal transmission by N-methyl-D-aspartate /[alpha]-amino-3-hydroxy-5-methylisoxazole-4-propionate receptors modulated by inhibitory [gamma]-amino-n-butyric acid type A receptors. Volatile anesthetics depress these oscillations by potentiating the inhibitory action of [gamma]-amino-n-butyric acid type A receptors, and as shown recently, indirectly by activation of adenosine A1-receptors. The purpose of this investigation was to study whether inactivation of adenosine A1-receptors can prevent the anesthetic-induced inhibition. Pretreatment of the hippocampal cultures with pertussis toxin prevents the inhibitory action of a specific adenosine A1-receptor agonist on the Ca(2+)-oscillations and also prevents the inhibition of the Ca(2+)-oscillations by halothane. This clearly shows the involvement of adenosine A1-receptors in the anesthetic-induced inhibition of the spontaneous calcium oscillations.
Tas
Piet W L
PW
Department of Anesthesiology, Center of Operative Medicine, Würzburg, Germany. tas_p@klinik.uni-wuerzburg.de
Roewer
Norbert
N
D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D000818:Animals; D020013:Calcium Signaling / Q000187:drug effects* / Q000502:physiology; D002478:Cells, Cultured; D006221:Halothane / Q000494:pharmacology*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D018613:Microscopy, Confocal; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D037342:Pertussis Toxin / Q000494:pharmacology; D051381:Rats; D043682:Receptor, Adenosine A1 / Q000187:drug effects* / Q000378:metabolism
D018685:Anesthetics, Inhalation; D043682:Receptor, Adenosine A1; D037342:Pertussis Toxin; D006221:Halothane