The cellular basis for burn-mediated cardiac dysfunction in adult
rabbits.
Horton, Jureta W.
Department of Surgery, The University of Texas Southwestern Medical
Center, Dallas, TX
APStracts 3:0245H, 1996.
We have shown that cutaneous burn injury impairs cardiac contractile
performance; however, the mechanisms remain unclear. In this study,
New Zealand White rabbits were anesthetized (isoflurane) and given a
full thickness scald burn over 30% of total body surface area and
resuscitated with lactated Ringer's solution, 4cc/kg/% burn for 24
hrs; rabbits handled in an identical fashion were given a sham burn
(SHAMS). Serum was obtained from burned and control rabbits,
aliquoted and frozen at -70 degrees ?C until assay. Neutrophils (PMN)
were isolated 24 hrs postburn from both sham and burned rabbits to
yield preps with >95% PMN with >95% viability. Cardiac
myocytes were isolated by retrograde perfusion of hearts with Ca2+
-free-collagenase-Tyrode's buffer, suspended in Kreb's Henseleit
buffer containing 10% fetal bovine serum and 1.8 mM Ca2+, and
incubated (1X105 cells/well) in a CO2 incubator under several
experimental conditions, including buffer alone, buffer plus 10% burn
serum, buffer plus 10% sham serum, or buffer plus either burn or sham
PMN (25x105/well). Myocyte viability (%) and creatine kinase (CK,
units/1x105 cells) were unchanged after incubation with sham plasma
or sham PMNs. Incubation of SHAM myocytes with burn plasma caused
viability to fall from 79+/-3 to 54+/-4, p<0.002 while CK rose
from 1639+/-115 to 2803+/-132, p<0.01. Similarly, incubation of
SHAM myocytes with burn PMN reduced viability from 83+/-2 to 50+/-3%,
p<0.01 while CK remained unchanged (1880+/- 168). Our data
indicate that circulating myocardial depressant factors after burn
injury contribute to cardiac myocyte injury.
Received 23 January 1996; accepted in final form 31 May 1996.
APS Manuscript Number H64-6.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 28 June 96