Scleral fibroblasts of the chick embryo proliferate by an autocrine mechanism in protein-free primary cultures: differential secretion of growth factors depending on the growth state.
Scleral fibroblasts of the chick embryo in primary culture proliferated in a protein-free medium. Conditioned medium (CdM) from the culture contained plural growth-promoting factors, which were active to the same cell type. The activity of one of the growth-promoting factors (SAF-I) was heat-resistant and the rest (SAF-II) were heat-sensitive. SAF-I accumulated in the CdM only during the growing phase; on the other hand, SAF-II accumulated in the CdM during the stationary phase. SAF-I showed the same time course of DNA synthesis-promoting activity as human PDGF. However, the activity of the SAF-I was not neutralized by anti-human PDGF. On the other hand, a part of the SAF-II (SAF-II a) showed a strong affinity for heparin.
Watanabe
K
K
Cell and Developmental Biology Laboratory, Faculty of Integrated Arts and Sciences, Hiroshima University, Japan.
Fujioka
M
M
Takeshita
T
T
Tsuda
T
T
Kawahara
A
A
Amano
M
M
D000818:Animals; D002455:Cell Division; D002478:Cells, Cultured; D002642:Chick Embryo; D003470:Culture Media; D046508:Culture Techniques / Q000379:methods; D004261:DNA Replication / Q000187:drug effects; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D006133:Growth Substances / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D012590:Sclera / Q000166:cytology*
D003470:Culture Media; D006133:Growth Substances; D007328:Insulin; D010982:Platelet-Derived Growth Factor