[Effect of growth hormone on the differentiation of chondrocytes from prepuberal rabbits in serum-free culture and on the radioimmunologic activity of Sm-C/IGF1 measured in the culture medium].
This study concerns the immunoreactive somatomedin C secretion by prepubertal rabbit epiphyseal chondrocytes cultured in a defined serum-free medium. In such culture conditions, chondrocytes mainly synthesized Type II collagen (80% of total collagen) during 10 days. A small amount of Type I collagen was also found with a significant (p less than 0.05) higher level during the period of cell multiplication (6.4 +/- 1.5%) than when cells reached confluency (0.9 +/- 0.2%). During the 10 days of culture without serum and without hormone added, a Sm-C/IGF1 activity was measured by RIA at a mean level of 30 +/- 5 mU/ml/10 micrograms DNA. This value was significantly higher (p less than 0.001) than in the medium not incubated with the cells (1.7 +/- 0.9 mU/ml). When hGH was added to the culture medium during the period of cell division, the level of Sm-C/IGF1 activity was significantly elevated at 39 +/- 4 mU/ml/10 micrograms DNA (p less than 0.05) and at 55 +/- 3 mU/ml/10 micrograms DNA (p less than 0.001) with 50 ng/ml and 100 ng/ml hGH concentrations respectively. On the contrary, no difference was observed at confluency in treated and non treated cells.
Corvol
M
M
INSERM U.30, Hôpital Necker-Enfants-Malades, Paris.
Dumontier
M F
MF
Prevot
C
C
Bonaventure
J
J
de la Tour
B
B
Willeput
J
J
D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D003094:Collagen / Q000096:biosynthesis; D013006:Growth Hormone / Q000494:pharmacology*; D006132:Growth Plate / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D011817:Rabbits; D012741:Sexual Maturation; D013002:Somatomedins / Q000378:metabolism*
D013002:Somatomedins; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D003094:Collagen
Effet de GH sur la différenciation de chondrocytes de lapin prépubère en culture sans sérum et sur l'activité radioimmunologique Sm-C/IGF1 measurable dans le milieu de culture.