title: Noninvasive quantification of superior mesenteric artery blood flow during sympathoneural activation in normal subjects.
abstract: The role of the splanchnic circulation in normal subjects during sympathoneural activation induced by stimuli which either raise (mental arithmetic, cold pressor test, isometric exercise) or maintain (head-up tilt) blood pressure has been studied by measuring superior mesenteric artery blood flow using a noninvasive Doppler ultrasound method in 18 normal subjects. Cardiac, systemic and regional haemodynamic changes were simultaneously studied. Blood pressure rose with the pressor tests and was maintained with head-up tilt. There was a significant fall in superior mesenteric artery blood flow with a rise in vascular resistance during each stimulus indicating active constriction. In six subjects, after 2 months measurements were repeated in an identical study. Superior mesenteric artery blood flow measurements in this study were closely correlated with the initial results. These changes, in a large vascular bed, are likely to be of importance in the overall haemodynamic response during sympathoneural stimuli which either raise or maintain blood pressure.
authors.affiliation: Department of Medicine, St Mary's Hospital Medical School, London, UK.
authors.forename: K R
authors.initials: KR
authors.lastname: Chaudhuri
authors.forename: T
authors.initials: T
authors.lastname: Thomaides
authors.forename: P
authors.initials: P
authors.lastname: Hernandez
authors.forename: M
authors.initials: M
authors.lastname: Alam
authors.forename: C J
authors.initials: CJ
authors.lastname: Mathias
mesh_terms: D000328:Adult; D001794:Blood Pressure; D003080:Cold Temperature; D005260:Female; D006339:Heart Rate; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008638:Mesenteric Arteries / Q000000981:diagnostic imaging / Q000294:innervation / Q000502:physiology*; D009131:Muscle, Smooth, Vascular / Q000000981:diagnostic imaging / Q000294:innervation / Q000502:physiology; D005082:Physical Exertion; D011187:Posture; D012016:Reference Values; D012039:Regional Blood Flow; D013850:Thinking; D014463:Ultrasonography