Evidence of cytokeratin expression in canine visceral glomerular epithelial cells in vivo.

Visceral glomerular epithelial cells (vGECs) originate from a mesenchymal blastema and transiently express cytokeratin during embryogenesis. There are no reports of cytokeratin expression in vGECs of mature, normal or damaged, human or other mammalian kidneys in vivo, but in vitro studies have provided evidence of the synthesis of cytokeratin in cultured vGECs. Cytokeratin expression was observed in vGECs in the damaged kidneys of four dogs with spontaneous renal diseases and, by using monoclonal antibodies, type 18 cytokeratin was identified. vGECs are apparently able to (re-) activate in vivo a mechanism for switching on the synthesis of cytokeratin in damaged glomeruli.