Cardiovascular Responsiveness to Vasopressin and alpha1-Adrenergic Receptor Agonists After Burn Injury Journal Article

Authors: Evans, A. E.; Vana, P. G.; LaPorte, H. M.; Kennedy, R. H.; Gamelli, R. L.; Majetschak, M
Article Title: Cardiovascular Responsiveness to Vasopressin and alpha1-Adrenergic Receptor Agonists After Burn Injury
Abstract: The effects of burn injury on cardiovascular responsiveness to vasoactive agents are not well understood. The aims of this study were to determine whether burn injury alters cardiovascular reactivity to vasoactive drugs in vivo and intrinsic function of isolated mesenteric resistance arteries. Anesthetized Sprague-Dawley rats were subjected to sham procedure or 30% TBSA dorsal scald burn, followed by crystalloid resuscitation (Parkland Formula). At 24, 72, 96, and 168 hours post burn, rats were reanesthetized, and the mean arterial blood pressure (MAP) responses to various doses of the alpha1-adrenergic receptor agonist phenylephrine and arginine vasopressin were tested. Mesenteric arteries were harvested from uninjured animals and at 24 and 168 hours post burn. The responsiveness of arteries to phenylephrine and arginine vasopressin was tested by pressure myography. Dose response curves were generated and EC50 concentrations, Hill slopes, and maximal effects were compared. The potency of phenylephrine to increase MAP was reduced 2-fold 24 hours post burn (P .05 vs sham) and gradually normalized at later time points. The reactivity of isolated arteries to phenylephrine was not significantly altered after burns. The potency of arginine vasopressin to increase MAP and to constrict isolated arteries was increased 2- to 3-fold at 24 hours post burn (P .05) and normalized at later time points. Our findings suggest that burn injury differentially regulates vasopressor and blood pressure effects of alpha-adrenergic and vasopressin receptor agonists. Intrinsic vasopressin receptor reactivity of resistance arteries is sensitized early after burns. These findings will help to optimize resuscitation strategies and vasopressor use in difficult to resuscitate burn patients.
Journal Title: Journal of burn care research : official publication of the American Burn Association
Volume: 38
Issue: 2
ISSN: 1559-0488; 1559-047X
Publisher: Unknown  
Journal Place: United States
Date Published: 2017
Start Page: 90
End Page: 98
Language: eng
Notes: LR: 20170303; GR: R01 GM107495/GM/NIGMS NIH HHS/United States; GR: T32 GM008750/GM/NIGMS NIH HHS/United States; JID: 101262774; NIHMS783299; PMCR: 2018/03/01; ppublish