Elevation of either axoplasmic norepinephrine or sodium level induced release of norepinephrine from cardiac sympathetic nerve terminals.
Using dialysis technique, prominent accumulation of norepinephrine (NE) in the myocardial interstitial space was observed under two different conditions: (1) local administration of a monoamine oxidase inhibitor (pargyline, 1, 10 mM), (2) local administration of a Na, K-ATPase inhibitor (ouabain, 10, 100 microM). Further, pretreatment with a vesicle uptake inhibitor (reserpine, 10 microM) augmented these responses. Either condition independently caused endogenous NE release and a brisk increase in dialysate NE levels might occur as a consequence of non-exocytotic release of NE.
Yamazaki
T
T
Department of Cardiac Physiology, National Cardiovascular Center Research Institute, Osaka, Japan.
Akiyama
T
T
Kitagawa
H
H
Takauchi
Y
Y
Kawada
T
T
D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology; D001369:Axons / Q000737:chemistry / Q000378:metabolism*; D002316:Cardiotonic Agents / Q000494:pharmacology; D002415:Cats; D005089:Exocytosis / Q000502:physiology; D005260:Female; D005728:Ganglia, Sympathetic / Q000187:drug effects / Q000201:enzymology*; D006321:Heart / Q000294:innervation; D008297:Male; D017551:Microdialysis; D008996:Monoamine Oxidase Inhibitors / Q000494:pharmacology; D009638:Norepinephrine / Q000378:metabolism*; D010042:Ouabain / Q000494:pharmacology; D010293:Pargyline / Q000494:pharmacology; D012110:Reserpine / Q000494:pharmacology; D012964:Sodium / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism
D000959:Antihypertensive Agents; D002316:Cardiotonic Agents; D008996:Monoamine Oxidase Inhibitors; D010042:Ouabain; D012110:Reserpine; D010293:Pargyline; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; D009638:Norepinephrine