title: Promotion of spheroid assembly of adult rat hepatocytes by some factor(s) present in the initial 6-hour conditioned medium of the primary culture.
abstract: Adult rat hepatocytes are capable of assembling to form floating multicellular spheroids (spheroids) in a dish with a positively charged surface in primary culture. In this report we show that the conditioned medium of the early time period of the culture exhibited biologically defined activity that promoted the assembly of isolated hepatocytes to floating spheroid. This activity was present only in the initial 6-hour conditioned medium; it was highest in the initial 2 h of culture and gradually decreased over 6 h and was not detected thereafter for 7 days. The conditioned medium appeared to inhibit the disintegration of spheroids that occurred during transfer to a new positively charged dish in the presence of either new or conditioned medium collected after day 4. Furthermore, disintegrated spheroids again assembled to form floating spheroid in the presence of the conditioned medium. Since the activity present in the conditioned medium was linearly dose-responsive to the inoculated viable cell number but not to that of dead cells, some factors responsible for the activity were probably produced by the viable cells during only a short time in culture.
authors.affiliation: First Department of Internal Medicine, Okayama University Medical School, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Sakaguchi
authors.forename: N
authors.initials: N
authors.lastname: Koide
authors.forename: K
authors.initials: K
authors.lastname: Asano
authors.forename: H
authors.initials: H
authors.lastname: Takabatake
authors.forename: H
authors.initials: H
authors.lastname: Matsushima
authors.forename: T
authors.initials: T
authors.lastname: Takenami
authors.forename: R
authors.initials: R
authors.lastname: Ono
authors.forename: S
authors.initials: S
authors.lastname: Sasaki
authors.forename: M
authors.initials: M
authors.lastname: Mori
authors.forename: Y
authors.initials: Y
authors.lastname: Koide
mesh_terms: D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D002452:Cell Count; D016923:Cell Death / Q000187:drug effects; D002478:Cells, Cultured; D003470:Culture Media / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D008099:Liver / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors
chemical_list: D003470:Culture Media