Characterization of an endothelial protein in the developing rabbit kidney.
A new protein (EnPo 1 antigen) abundant on endothelial cells and glomerular podocytes has been characterized by means of the mouse monoclonal antibody EnPo 1. Following electrophoretical separation of rabbit kidney homogenates EnPo 1 recognized a protein with a molecular weight of 110 kDa and an isoelectric point of 5.9 in Western blots. Using immunohistological techniques, the EnPo 1 antigen has been localized in high concentrations on glomerular podocytes of different developmental stages. Furthermore, the EnPo 1 antigen was expressed on endothelial cells of all adult rabbit organs tested so far. Detailed analysis of neonatal rabbit kidney revealed the abundance of EnPo 1 antigen on both differentiated vessels as well as on immature endothelial cells and endothelium of the microvasculature. Thus, for the first time a marker for in situ investigations of angiogenic processes within the mammalian kidney is available. Analysis of kidney cryosections by confocal laser scan microscopy revealed a direct connection between mature and differentiating vessels in the outer kidney cortex. Furthermore, two differentially organized cell populations discriminated by their EnPo 1 binding pattern were localized in the embryonic renal cortex. Morphologically, these cells were not distinguishable from other mesenchymal cells.
Kloth
S
S
Department of Anatomy, University of Regensburg, Federal Republic of Germany.
Meyer
D
D
Röckl
W
W
Miettinen
A
A
Aigner
J
J
Schmidbauer
A
A
Minuth
W W
WW
D000818:Animals; D000831:Animals, Newborn; D000911:Antibodies, Monoclonal; D000941:Antigens / Q000032:analysis*; D004730:Endothelium, Vascular / Q000737:chemistry* / Q000254:growth & development; D007668:Kidney / Q000098:blood supply / Q000737:chemistry / Q000254:growth & development; D007678:Kidney Glomerulus / Q000737:chemistry* / Q000254:growth & development; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D009389:Neovascularization, Pathologic / Q000378:metabolism; D011817:Rabbits; D051381:Rats; D017208:Rats, Wistar
D000911:Antibodies, Monoclonal; D000941:Antigens