RENIN RESPONSE TO HEMORRHAGE IN AWAKE AND ANESTHETIZED RATS

  • 1 January 1979
    • journal article
    • research article
    • Vol. 6  (3) , 271-276
Abstract
Anesthetic agents alter survival in animals subjected to hemorrhage. Since survival after hemorrhage is increased by inhibitors of the renin-angiotensin system, the effect of anesthetic agents on renin release during hemorrhage was studied. Rats (33) were subjected to 1 h of hemorrhagic hypotension at a mean arterial pressure of 40 mm Hg. Animals were either awake or anesthetized with halothane or ketamine. Anesthesia alone did not alter plasma renin activity (PRA), whereas hemorrhage resulted in approximately a 10-fold increase in PRA in both awake and anesthetized animals. After the shed blood was returned to the animal, i.v. saralasin, an angiotensin II competitive inhibitor, produced a 21-24 mm Hg decrease in blood pressure in all animals, regardless of the anesthetic exposure. The increase in PRA that accompanies severe hemorrhage is unaltered by halothane or ketamine anesthesia, the renin-angiotensin system provides a similar amount of blood pressure support in both awake and anesthetized animals, and the anesthetic influence on survival following severe hemorrhage does not result from anesthetic-induced alterations of the renin-angiotensin system.