Age-related differences in response to neutrophil-mediated reperfusion injury in the neonatal piglet heart.
BACKGROUND
Neonatal hearts have altered adhesion molecule interactions in response to ischemia-reperfusion. How this affects myocardial function is unknown.


METHODS
Isolated, buffer perfused 0- to 2-day (newborn) and 2-week piglet hearts were first subjected to 20-minute global, normothermic ischemia, followed by 45 minutes of reperfusion during which 150 x 10(6) newborn or 2-week neutrophils were infused. In some hearts, an antibody to SLe(x) (CSLEX-1) was infused with neutrophils during reperfusion. Hemodynamic variables, including left ventricular developed pressure (LVDP), were recorded at timed intervals. Neutrophil CD-18, L-selectin, and SLe(x) contents were measured by flow cytometry.


RESULTS
Full recovery of LVDP was observed in newborn hearts receiving newborn or 2-week-old neutrophils. Recovery of LVDP was depressed (p < 0.01, ANOVA) in 2-week-old hearts receiving 2-week old, not newborn, neutrophils. Infusion of CSLEX-1 in 2-week-old hearts restored LVDP to baseline. Whereas flow cytometry showed higher (p < 0.01, Student's t test) CD-18 and L-selectin expression on newborn versus 2-week-old neutrophils, newborn neutrophils expressed lower (p < 0.01) SLe(x) levels.


CONCLUSIONS
Initial "loose" neutrophil-endothelial selectin interactions are a necessary prelude to "firm" adhesion and reperfusion injury. Operations performed soon after birth may be better tolerated than when surgery is delayed; anti-SLe(x) preparations may prove beneficial when performing cardiac procedures on older infants.
Keller
V A
VA
Department of Surgery, Tulane University School of Medicine, New Orleans, La. 70112, USA.
Pigott
J D
JD
Flint
L M
LM
Hart
K K
KK
Lefer
D J
DJ
Ferrara
J J
JJ
D000818:Animals; D000831:Animals, Newborn; D000911:Antibodies, Monoclonal; D001713:Biphenyl Compounds / Q000494:pharmacology; D018821:CD18 Antigens / Q000378:metabolism; D002634:Chemotaxis, Leukocyte; D003326:Coronary Circulation; D006339:Heart Rate; D006439:Hemodynamics; D019041:L-Selectin / Q000378:metabolism; D016256:Lewis X Antigen / Q000378:metabolism; D008358:Mannose / Q000031:analogs & derivatives; D008362:Mannosides / Q000494:pharmacology; D009504:Neutrophils / Q000502:physiology*; D015427:Reperfusion Injury / Q000473:pathology / Q000503:physiopathology*; D013552:Swine
D000911:Antibodies, Monoclonal; D001713:Biphenyl Compounds; D018821:CD18 Antigens; D016256:Lewis X Antigen; D008362:Mannosides; D019041:L-Selectin; C108700:bimosiamose disodium; D008358:Mannose