Hypothermia augments polymorphonuclear leukocyte degranulation and interleukin-8 production from human umbilical vein endothelial cells and increases lipopolysaccharide-induced polymorphonuclear leukocyte-endothelial cell interaction when followed by normothermia.
OBJECTIVE
To determine if hypothermia followed by normothermia (rewarmed to 37 degrees C) changes the inflammatory response of polymorphonuclear leukocytes (PMNs) and human umbilical vein endothelial cells (HUVEC).


METHODS
Prospective, controlled, in vitro study.


METHODS
University laboratory.


METHODS
PMNs from 4 healthy volunteers and HUVEC.


RESULTS
PMNs and HUVEC were incubated for 3 hours at 20 degrees C, 30 degrees C, or 37 degrees C followed by 37 degrees C again. PMN degranulation, cytokine production from HUVEC, and PMN-HUVEC interaction were compared among the 3 experimental temperatures. Interleukin (IL)-8-induced PMN degranulation measured by myeloperoxidase concentrations was significantly higher in the 20 degrees C and 30 degrees C groups than the 37 degrees C groups. Bacterial lipopolysaccharide (LPS)-induced IL-8 production from HUVEC, measured by enzyme-linked immunosorbent assay, was significantly higher in the 20 degrees C group than the other 2 groups; however, tumor necrosis factor-alpha was not detectable in any of the groups. LPS-induced cell injury measured by cellular (51)Cr release was significantly higher in the 20 degrees C and 30 degrees C groups than in the 37 degrees C groups. This injury was significantly inhibited by IL-8 antibody.


CONCLUSIONS
Hypothermic (20 degrees C and 30 degrees C) incubation followed by rewarming augmented IL-8-induced PMN degranulation and LPS-induced IL-8 production from HUVEC and LPS-induced PMN-endothelial interaction. IL-8 plays an important role in this increased injury. This increased inflammatory response may support the positive outcomes of normothermic CPB.
Sakao
Yukinori
Y
Department of Biochemistry, The University of Texas Health Center at Tyler, Tyler, TX, USA.
Nakahara
Yoshiaki
Y
Carr
Ferdicia K
FK
Miller
Edmund J
EJ
D002315:Cardiopulmonary Bypass; D002450:Cell Communication; D015550:Cell Degranulation; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D007036:Hypothermia, Induced; D016209:Interleukin-8 / Q000096:biosynthesis*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D009504:Neutrophils / Q000502:physiology*; D009195:Peroxidase / Q000378:metabolism; D011446:Prospective Studies; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis; D014471:Umbilical Veins
D016209:Interleukin-8; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha; D009195:Peroxidase