Systemic and hepatosplanchnic macro- and microcirculatory dose response to arginine vasopressin in endotoxic rabbits.
OBJECTIVE
Arginine vasopressin (AVP) is being used increasingly to treat vasodilatory hypotension, although its effects on hepatosplanchnic perfusion have been debated.


METHODS
Prospective study in a university-based experimental research laboratory.


METHODS
We compared the effect of AVP on systemic, gut, and liver blood flow in anesthetized and ventilated rabbits given either saline or endotoxin. Incremental i.v. boluses of AVP ranging from 1 to 1,000[Symbol: see text]ng were administered 90[Symbol: see text]min post-endotoxin or saline.


RESULTS
Endotoxin induced a shock state with a transient decrease of mesenteric artery blood flow velocity (pulsed Doppler, in centimeters per second, V(mes)) but had no effect on liver surface microcirculation (laser Doppler in TPU, MicroFl(liver)). Gut microcirculatory (MicroFl(gut)) changes became independent of mean arterial pressure (MAP) after endotoxin. In control rabbits (n = 5), increasing doses of AVP elevated MAP but reduced aortic blood flow (pulsed Doppler, VAo), V(mes), and MicroFl(gut) (p < 0.05). In endotoxic animals (n = 6), AVP produced a similar rise in MAP (p < 0.05), while V(mes) and MicroFl(gut) only decreased for AVP doses above 100[Symbol: see text]ng (p < 0.05). Liver microcirculation was only minimally affected by AVP, although significantly, both in control and endotoxin animals.


CONCLUSIONS
Preservation of mesenteric blood flow as well as gut and liver microcirculation, with therapeutic doses of AVP during endotoxemia, supports its use as a hemodynamic agent during septic shock.
Kopel
Tal
T
Critical Care Division, Royal Victoria Hospital, 687 Pine Av. West, H3A 1A1, Montreal, QC, Canada.
Losser
Marie-Reine
MR
Faivre
Valérie
V
Payen
Didier
D
D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology / Q000627:therapeutic use*; D004195:Disease Models, Animal; D006439:Hemodynamics / Q000187:drug effects; D007022:Hypotension / Q000188:drug therapy*; D007422:Intestines / Q000098:blood supply*; D008099:Liver / Q000098:blood supply*; D008833:Microcirculation / Q000187:drug effects*; D011817:Rabbits; D012772:Shock, Septic / Q000188:drug therapy; D013152:Splanchnic Circulation / Q000187:drug effects*; D014662:Vasoconstrictor Agents / Q000494:pharmacology / Q000627:therapeutic use*
D014662:Vasoconstrictor Agents; D001127:Arginine Vasopressin