CYTOKERATIN-POSITIVE AND CYTOKERATIN-NEGATIVE CULTURED ENDOTHELIAL-CELLS FROM BOVINE AORTA AND VENA-CAVA

The heterogeneous morphology of microvascular endothelial cells obtain ed from the bovine corpus luteum was recently attributed to the occurr ence of cytokeratin (CK) positive and CK negative endothelial cells. T he aim of the present study was to establish comparable differences fo r bovine macrovascular endothelial cells. For this reason, endothelial cells were scraped from the abdominal aorta as well as the inferior v ena cava of cows. At the level of phase contrast microscopy primary cu ltures originating from both large vessels could be classified as CK p ositive or CK negative endothelial cells. After seeding CK positive en dothelial cells on Matrigel matrix, a two-dimensional meshwork of so c alled pseudotubules formed within 2 h. By using immunofluorescence loc alization CK positive cells were identified by a complex meshwork. It consisted of CE 8, is and 19 as displayed by Western blots. The CK neg ative group showed spindle-shaped or polygonal endothelial cells accor ding to light microscopy. In postconfluent cultures, spindle-shaped ce lls developed a three-dimensional meshwork of tubules. After seeding s pindle-shaped cells on Vitrogen 100 matrix, pseudotubules formed withi n 1 day. In considering the frequency of occurrence, primary harvests from the vena cava contained less than 1% CK positive cells. With resp ect to growth, the cell number was two to three times higher for the C K negative group than the CK positive group as judged on day 13 after cell seeding. It is concluded that subpopulations of endothelial cells are derived from large blood vessels.