Vagosympathetic interactions in ischemia-induced myocardial norepinephrine and acetylcholine release.
To elucidate the pathophysiological roles of vagosympathetic interactions in ischemia-induced myocardial norepinephrine (NE) and acetylcholine (ACh) release, we measured myocardial interstitial NE and ACh levels in response to a left anterior descending coronary occlusion in the following groups of anesthetized cats: intact autonomic innervation (INT, n = 7); vagotomy (VX, n = 6); local administration of atropine (Atro, n = 6); transection of the stellate ganglia (TSG, n = 5); local administration of phentolamine (Phen, n = 6); and combined vagotomy and transection of the stellate ganglia (VX+TSG, n = 5). The maximum NE release was enhanced in the VX group (141 +/- 30 nmol/l, means +/- SE, P < 0.05) compared with the INT group (61 +/- 12 nmol/l). Neither the Atro (50 +/- 24 nmol/l) nor VX+TSG groups (84 +/- 25 nmol/l) showed enhanced NE release. The maximum ACh release was unaltered in the TSG and Phen groups compared with the INT group (19 +/- 4, 18 +/- 4, and 13 +/- 3 nmol/l, respectively). These findings indicate that the cardiac vagal afferent but not efferent activity reduced the ischemia-induced myocardial NE release. In contrast, the cardiac sympathetic afferent and efferent activities played little role in the ischemia-induced myocardial ACh release.
Kawada
T
T
Department of Cardiovascular Dynamics, National Cardiovascular Center Research Institute, Osaka 565-8565, Japan. torukawa@res.ncvc.go.jp
Yamazaki
T
T
Akiyama
T
T
Inagaki
M
M
Shishido
T
T
Zheng
C
C
Yanagiya
Y
Y
Sugimachi
M
M
Sunagawa
K
K
D000109:Acetylcholine / Q000378:metabolism / Q000502:physiology*; D000344:Afferent Pathways; D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D002415:Cats; D004525:Efferent Pathways; D005728:Ganglia, Sympathetic / Q000187:drug effects / Q000502:physiology; D006339:Heart Rate / Q000502:physiology; D066298:In Vitro Techniques; D017551:Microdialysis; D017202:Myocardial Ischemia / Q000378:metabolism* / Q000503:physiopathology; D009206:Myocardium / Q000378:metabolism*; D009638:Norepinephrine / Q000378:metabolism / Q000502:physiology*; D013564:Sympathetic Nervous System / Q000503:physiopathology*; D014628:Vagotomy; D014630:Vagus Nerve / Q000503:physiopathology*
D000109:Acetylcholine; D009638:Norepinephrine