title: Renewal of alveolar epithelium in the rat following exposure to NO2.
abstract: This research was undertaken to study the kinetics of Type 2 cell division and the fate of the Type 2 sister cell following exposure to NO(2). To accomplish this, male rats were exposed to NO(2). Dividing cells were labeled with (3)H-TdR and studied with autoradiographic technics in the light and electron microscopes for up to 72 hours after labeling. The kinetics of cell division were determined from a curve constructed from the percent of labeled mitotic figures. The fate of the Type 2 sister cells was determined by studying tissues at 24, 48 and 72 hours after labeling with (3)H-TdR. The results show that Type 2 cells may divide and the sister cells transform into Type 1 cells. These data support an interpretation of the mechanism for cell renewal of the alveolar epithelium in which Type 2 cells are the progenitor cells for Type 1 cells.
mesh_terms: D000818:Animals; D001345:Autoradiography; D001485:Basement Membrane / Q000166:cytology; D002455:Cell Division / Q000187:drug effects*; D004781:Environmental Exposure; D004847:Epithelial Cells; D004848:Epithelium / Q000187:drug effects; D006652:Histological Techniques; D007700:Kinetics; D008297:Male; D008854:Microscopy, Electron; D009585:Nitrogen Dioxide / Q000494:pharmacology*; D011650:Pulmonary Alveoli / Q000166:cytology* / Q000187:drug effects; D051381:Rats; D013936:Thymidine / Q000378:metabolism; D013997:Time Factors; D014316:Tritium
chemical_list: D014316:Tritium; D009585:Nitrogen Dioxide; D013936:Thymidine