title: Either desipramine or TMB-8 suppresses cyanide-induced norepinephrine efflux from in vivo cardiac sympathetic nerves of cats.
abstract: To investigate the effect of hypoxia on endogenous norepinephrine (NE) release from cardiac sympathetic nerve ending, we administered sodium cyanide (NaCN) for 30 min into the myocardial interstitial space through a dialysis probe and measured dialysate NE levels. During the NaCN perfusion, a marked and concentration-dependent increase in dialysate NE was observed. This cyanide-induced NE response was suppressed by pretreatment with despiramine (a membraneous NE transport inhibitor). Furthermore, the cyanide-induced NE response was suppressed by pretreatment with TMB-8 (intracellular Ca(2+) antagonist) but unaffected by omega-conotoxin GVIA (NE releasing inhibitor). Our data suggest that two (desipramine or TMB-8 suppressive) mechanisms contributed to the amount of NE efflux induced by cyanide in in vivo cardiac sympathetic nerve.
authors.affiliation: Department of Cardiac Physiology, Research Institute, National Cardiovascular Center, Suita, Osaka, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Yahagi
authors.forename: T
authors.initials: T
authors.lastname: Yamazaki
authors.forename: T
authors.initials: T
authors.lastname: Akiyama
mesh_terms: D000818:Animals; D000929:Antidepressive Agents, Tricyclic / Q000494:pharmacology*; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D002415:Cats; D003486:Cyanides / Q000494:pharmacology*; D003891:Desipramine / Q000494:pharmacology*; D004195:Disease Models, Animal; D004347:Drug Interactions / Q000502:physiology*; D005260:Female; D005707:Gallic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D006321:Heart / Q000187:drug effects* / Q000294:innervation* / Q000502:physiology*; D008297:Male; D017551:Microdialysis; D017202:Myocardial Ischemia / Q000139:chemically induced / Q000503:physiopathology; D009206:Myocardium / Q000166:cytology* / Q000378:metabolism*; D009638:Norepinephrine / Q000378:metabolism*; D017779:Sympathetic Fibers, Postganglionic / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*
chemical_list: D000929:Antidepressive Agents, Tricyclic; D002121:Calcium Channel Blockers; D003486:Cyanides; C006014:8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate; D005707:Gallic Acid; D003891:Desipramine; D009638:Norepinephrine