title: Differential expression of platelet-endothelial cell adhesion molecule-1 (PECAM-1) in murine tissues.
abstract: OBJECTIVE
  To characterize and compare the expression of PECAM-1 in unstimulated and tumor necrosis factor alpha-(TNF-alpha)-stimulated tissues of mice.
  
  
  METHODS
  Binding and non-binding monoclonal antibodies (mAb) were radiolabeled and injected into wild-type mice and mice deficient of P-selectin, CD18, or ICAM-1. The relative accumulation of binding mAb (PECAM-1 mAb) was determined in wild-type mice following a 25 micrograms/kg i.p. injection of TNF-alpha and in mutant mice under basal conditions.
  
  
  RESULTS
  Under unstimulated conditions, PECAM-1 was significantly expressed in all tissues examined, with no changes occurring after TNF-alpha stimulation. An equivalence of PECAM-1 expression was observed in unstimulated tissues among wild-type mice and mice that are genetically deficient in either CD18, ICAM-1, or P-selectin. The level of PECAM-1 expression in different vascular beds was highly correlated to published values of endothelial surface area. Normalization of previously published values of ICAM-1, VCAM-1, E- and P-selectin expression relative to PECAM-1 expression in the same tissues revealed a diminished organ-to-organ variability in expression of the different adhesion molecules. Estimates of adhesion molecule expression in lung and brain were most profoundly affected by normalization to PECAM-1 expression.
  
  
  CONCLUSIONS
  These findings support the use of PECAM-1 expression in regional vascular beds as an indicator of endothelial cell surface area.
authors.affiliation: Department of Molecular and Cellular Physiology, Louisiana State University Medical Center, Shreveport 71130-3932, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Eppihimer
authors.forename: J
authors.initials: J
authors.lastname: Russell
authors.forename: R
authors.initials: R
authors.lastname: Langley
authors.forename: G
authors.initials: G
authors.lastname: Vallien
authors.forename: D C
authors.initials: DC
authors.lastname: Anderson
authors.forename: D N
authors.initials: DN
authors.lastname: Granger
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D018821:CD18 Antigens / Q000235:genetics / Q000378:metabolism; D004730:Endothelium, Vascular / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008833:Microcirculation / Q000378:metabolism*; D019007:P-Selectin / Q000235:genetics / Q000378:metabolism; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000494:pharmacology; D014018:Tissue Distribution; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D000911:Antibodies, Monoclonal; D018821:CD18 Antigens; D019007:P-Selectin; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D018799:Intercellular Adhesion Molecule-1