title: A highly sensitive bioassay for PTH using ROS 17/2.8 subclonal cells.
abstract: A highly sensitive bioassay for PTH was developed by using rat osteosarcoma cells (ROS 17/2.8). By limiting dilution, ROS cells were subcloned and the subclonal cell line (ROS 17/2.8-5) most responsive to PTH was selected. When subconfluent ROS 17/2.8-5 cells were treated with hydrocortisone for 3 days and then incubated with PTH, the cAMP response was significant at 10-40 ng/l hPTH (1-34) (4 approximately 16 X 10(-12) mol/l). Osteoclast activating factors such as human interleukin 1 alpha and beta, and tumour necrosis factor alpha did not stimulate cAMP production, whereas a conditioned medium of oesophageal carcinoma cells established from a patient with humoral hypercalcaemia stimulated cAMP production. By selecting PTH-responsive subclonal cells and treating them with hydrocortisone, the sensitivity for detecting PTH was improved approximately 15 times. This method will be useful in the characterization and purification of PTH-like factors produced by malignant tumours from hypercalcaemic patients.
authors.affiliation: Institute of Clinical Endocrinology, Tokyo Women's Medical College, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Sato
authors.forename: D C
authors.initials: DC
authors.lastname: Han
authors.forename: M
authors.initials: M
authors.lastname: Ozawa
authors.forename: Y
authors.initials: Y
authors.lastname: Fujii
authors.forename: T
authors.initials: T
authors.lastname: Tsushima
authors.forename: K
authors.initials: K
authors.lastname: Shizume
mesh_terms: D000818:Animals; D001681:Biological Assay / Q000379:methods*; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D000242:Cyclic AMP / Q000096:biosynthesis; D006854:Hydrocortisone / Q000008:administration & dosage; D008222:Lymphokines / Q000378:metabolism; D012516:Osteosarcoma / Q000378:metabolism; D010281:Parathyroid Hormone / Q000378:metabolism*; D011817:Rabbits
chemical_list: D008222:Lymphokines; D010281:Parathyroid Hormone; C008718:osteoclast activating factor; D000242:Cyclic AMP; D006854:Hydrocortisone