Augmentation of sympathetic venoconstriction by angiotensin II in human dorsal hand veins.
The constriction produced by a single deep breath was measured simultaneously in two adjacent hand veins in normal subjects. One vein was infused with saline or angiotensin II; the other acted as a control. A dose of angiotensin II (1 pmol/min) that did produce venous constriction directly significantly augmented the constriction caused by deep breath in eight subjects (P less than .01). In a further six subjects the same dose had no effect on venoconstriction caused by infused noradrenaline. We conclude that angiotensin II causes venoconstriction indirectly by augmenting sympathetically mediated responses, possibly by a presynaptic mechanism.
Webb
D J
DJ
Department of Clinical Pharmacology, St. George's Hospital Medical School, London, UK.
Benjamin
N
N
Cockcroft
J R
JR
Collier
J G
JG
D000328:Adult; D000804:Angiotensin II / Q000008:administration & dosage*; D005260:Female; D006225:Hand / Q000098:blood supply*; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000008:administration & dosage; D012018:Reflex / Q000187:drug effects; D013564:Sympathetic Nervous System / Q000187:drug effects*; D014661:Vasoconstriction / Q000187:drug effects*; D014680:Veins / Q000187:drug effects / Q000502:physiology
D000804:Angiotensin II; D009638:Norepinephrine