Oxygen consumption after massive sympathetic nervous system discharge.
We evaluated the possibility that massive, sympathetic nervous system (SNS) activation [as may precede the development of neurogenic pulmonary edema (NPE)] increases O2 demand. O2 consumption (VO2) and plasma concentrations of the calorigenic agents, epinephrine (EPI) and norepinephrine (NE) were measured in alpha-chloralose-anesthetized dogs under control conditions and for 3 h after the administration of either 1) intracisternal (ic) veratrine to activate the SNS, 2) intravenous (iv) veratrine, 3) ic saline, or 4) ic veratrine, after clamping the adrenal blood vessels. VO2 increased 31.7 +/- 3.6% (SE), and EPI and NE increased to, respectively, 30,853 +/- 8,347 and 8,176 +/- 2,104 pg/ml in the ic veratrine group. No increases in VO2 and EPI and attenuated increases in NE were observed in the ic veratrine animals with clamped adrenals. No significant increases in VO2 or catecholamine concentrations were observed after ic saline or iv veratrine administration. These data suggest that the elevated VO2 may have been mediated by adrenal catecholamines and that an increased metabolic rate may complicate the ability of patients with severe NPE to balance O2 supply with demand.
Lang
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SA
Department of Physiology, Northeastern Ohio Universities, College of Medicine, Rootstown 44272.
Maron
M B
MB
Signs
S A
SA
D000311:Adrenal Glands / Q000502:physiology; D000818:Animals; D001794:Blood Pressure; D002302:Cardiac Output / Q000187:drug effects; D004285:Dogs; D004837:Epinephrine / Q000097:blood; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D009638:Norepinephrine / Q000097:blood; D010101:Oxygen Consumption / Q000187:drug effects; D011651:Pulmonary Artery / Q000187:drug effects / Q000502:physiology / Q000503:physiopathology; D011654:Pulmonary Edema / Q000503:physiopathology; D012016:Reference Values; D013564:Sympathetic Nervous System / Q000502:physiology* / Q000503:physiopathology; D014702:Veratrine / Q000494:pharmacology
D014702:Veratrine; D009638:Norepinephrine; D004837:Epinephrine