title: Limited division of low-density adult rat type II pneumocytes in serum-free culture.
abstract: A previously reported serum-free medium for the culture of adult rat type II pneumocytes has been further defined by the addition of 10 mM N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid buffer and 700 U/ml catalase. Both additions significantly enhanced [3H]thymidine incorporation into pneumocyte DNA between days 5 and 6 of culture. In the presence of 100 micrograms/ml bovine pituitary extract, both insulin-like growth factor (IGF) I (20 ng/ml) and II (25 ng/ml) further increased [3H]thymidine incorporation into pneumocyte DNA over that observed with the basal medium. When type II pneumocytes were plated at 2.75 X 10(5) cells/cm2 there was a plating efficiency of 50 +/- 5%, and the increased DNA synthesis in response to IGFs was not associated with an increase in cell number. When the plating number was reduced to 1.6 X 10(5) cells/cm2 the plating efficiency was only 23 +/- 2%. At this low cell density a doubling of cell number was observed in response to IGF-I between days 4 and 9 of culture.
authors.affiliation: Department of Medicine, St. Michael's Hospital, University of Toronto, Ontario, Canada.
authors.forename: A K
authors.initials: AK
authors.lastname: Tanswell
authors.forename: P J
authors.initials: PJ
authors.lastname: Byrne
authors.forename: R N
authors.initials: RN
authors.lastname: Han
authors.forename: J D
authors.initials: JD
authors.lastname: Edelson
authors.forename: V K
authors.initials: VK
authors.lastname: Han
mesh_terms: D000818:Animals; D001769:Blood; D002417:Cattle; D002455:Cell Division / Q000187:drug effects; D002469:Cell Separation / Q000379:methods; D002478:Cells, Cultured; D003470:Culture Media; D046508:Culture Techniques / Q000379:methods; D004261:DNA Replication / Q000187:drug effects; D005109:Extracellular Matrix / Q000502:physiology; D005353:Fibronectins / Q000494:pharmacology; D006728:Hormones / Q000494:pharmacology*; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D007335:Insulin-Like Growth Factor II / Q000494:pharmacology; D007700:Kinetics; D007797:Laminin / Q000494:pharmacology; D008168:Lung / Q000166:cytology* / Q000187:drug effects; D010902:Pituitary Gland / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D013936:Thymidine / Q000378:metabolism; D014020:Tissue Extracts / Q000494:pharmacology
chemical_list: D003470:Culture Media; D005353:Fibronectins; D006728:Hormones; D007797:Laminin; D014020:Tissue Extracts; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D013936:Thymidine