title: Establishment of 8-azaguanine-resistant mutants from rat thyroid cell line FRTL-5.
abstract: 8-Azaguanine (AG)-resistant mutant clones were isolated from FRTL-5 rat thyroid cells, by treating them with ethylmethane sulfonate for 48 h and then, after the recovery period, by selecting them in AG-containing medium. Isolated mutants were further selected in 6-thioguanine-containing medium, and two mutant clones were finally obtained (AG1 and AG2). The mutants retained several thyroid stimulating hormone (TSH) responsiveneses following acquisition of AG resistance: they responded to bovine TSH (bTSH), by producing cyclic 3',5'-adenosine monophosphate (cAMP) and thyroglobulin, and taking up iodine. However, TSH-responsive profiles were slightly different from each other in several points. They were killed in hypoxanthine-aminopterin-thymidine (HAT)-selective medium and applied to cell hybridization study with human thyrocyte from a Graves' patient: the hybrid turned out to produce both rat and human thyroglobulin even 12 months after the hybridization.
authors.affiliation: Second Division of Internal Medicine, Kyoto University School of Medicine, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Sugawa
authors.forename: T
authors.initials: T
authors.lastname: Mori
authors.forename: H
authors.initials: H
authors.lastname: Imura
mesh_terms: D000818:Animals; D001375:Azaguanine / Q000494:pharmacology*; D002455:Cell Division; D002459:Cell Fusion; D002460:Cell Line; D000242:Cyclic AMP / Q000096:biosynthesis; D004351:Drug Resistance; D006801:Humans; D007455:Iodine / Q000378:metabolism; D009154:Mutation; D051381:Rats; D013936:Thymidine / Q000378:metabolism; D013954:Thyroglobulin / Q000378:metabolism; D013961:Thyroid Gland / Q000166:cytology / Q000378:metabolism*; D013972:Thyrotropin / Q000378:metabolism / Q000494:pharmacology; D014284:Triiodothyronine / Q000378:metabolism
chemical_list: D014284:Triiodothyronine; D013972:Thyrotropin; D013954:Thyroglobulin; D007455:Iodine; D000242:Cyclic AMP; D001375:Azaguanine; D013936:Thymidine