E- and P-selectin expression depends on the resuscitation fluid used in hemorrhaged rats

Background. E- and P-selectins are adhesion molecules that effect neutrophi l-mediated reperfusion injury. Our hypothesis was that the expression of E- and P-selectins is dependent on the type of fluid used for resuscitation a nd that lactated Ringer's (LR) solution would result in an early upregulati on of these molecules. Methods. Male Sprague-Dawley rats (n = 36) were subjected to a 27 ml/kg hem orrhage over 5 min followed by a l-h shock period and l-h of resuscitation. The animals were randomized into the following resuscitation groups: (1) s ham; (2) hemorrhage, no resuscitation; (3) whole blood (27 ml/kg); (4) 3:1 lactated Ringer's (81 ml/kg); (5) sham hemorrhage, infusion of lactated Rin ger's (81 ml/kg); (6) 7.5% hypertonic saline (9.7 ml/kg). Immediately after resuscitation, the spleen and lung were harvested for measurement of E- an d P-selectin mRNA expression with reverse transcriptase- polymerase chain r eaction (RT-PCR), and protein expression with immunostaining. Results. LR resuscitation and LR infusion without prior hemorrhage signific antly increased the E- and P-selectin mRNA in the lung and spleen. Immunost aining demonstrated that the adhesion molecule expression was mainly locate d in perivascular/peribronchial areas in the lung, and the marginal and tra becular areas in the spleen. Pulmonary edema and inflammatory cell infiltra tion were observed only in the animals that were hemorrhaged and resuscitat ed with LR. No resuscitation and resuscitation with whole blood caused no s ignificant increase in selectin expression. Conclusion. LR resuscitation and LR infusion without hemorrhage are associa ted with early increased expression of E- and P-selectin molecules in the l ung and spleen. (C) 2000 Academic Press.