THE INFLUENCE OF NALOXONE ON REGIONAL HEMODYNAMICS IN HEMORRHAGED RATS

  • 1 January 1985
    • journal article
    • research article
    • Vol. 16  (2) , 173-183
Abstract
Naloxone increases arterial pressure in hemorrhaged animals, but its effects on organ blood flows are not well established. Central and regional hemodynamics were measured immediately before and 25 min or 55 min after hemorrhage in 33 anesthetized rats. Fifteen min after the beginning of hemorrhage, animals received either vehicle (n = 17) or naloxone (n = 16), 10 mg/kg i.v. At 25 min, animals treated with naloxone had a greater blood flow to the left cerebral hemisphere than those receiving vehicle, but all other measurements were similar. At 55 min, the mean arterial pressure and heart rate were greater in animals treated with naloxone, but blood flow was increased to the spleen only. Vascular resistance values were greater in the gastrointestinal tract and less in the spleen in animals receiving naloxone. In anesthetized rats, naloxone increased mean arterial pressure and splenic blood flow and transiently increased cerebral blood flow, but other regional flows and cardiac output were similar to those in rats receiving vehicle only.