K. Abdi et al., IN-SITU FLUORESCENCE LABELING OF SHEEP LUNG MICROVASCULAR ENDOTHELIUM, In vitro cellular & developmental biology. Animal, 31(4), 1995, pp. 310-315
Endothelial cells are intimately involved in a variety of biological p
rocesses such as inflammatory disorders, wound healing, and tumor inva
sion. The finding of endothelial heterogeneity in various tissues has
led to major efforts to isolate and culture microvascular endothelial
cells in human and animal tissue. In this report we have used phosphat
idyl ethanolamine (PE)-labeled liposomes to fluorescently label the sh
eep lung microvasculature in situ. Using normotensive perfusion pressu
re, the PE-labeled liposomes did not extravasate into extravascular lu
ng tissue. Mechanical and enzymatic digestion of the lung tissue demon
strated that the PE-labeled liposomes provided a stable label of the v
ascular lining cells during ex vivo processing. After digestion, the o
verwhelming majority of the fluorescent label appeared in cellular agg
regates, Approximately 80% of these cells demonstrated an in vitro phe
notype consistent with microvascular endothelium. A novel monoclonal a
ntibody selective for sheep endothelial cells was developed to confirm
the presence of lung endothelium in the fluorescently labeled cellula
r aggregates. We conclude that in situ fluorescence labeling of vascul
ar lining cells provides an anatomic marker for relevant vascular lini
ng cells and an opportunity to study these cells in vitro.