Stimulation of insulin-like growth factor I production in primary cultures of chicken hepatocytes by chicken growth hormone.
Extracts of conditioned media from primary cultures of chicken hepatocytes stimulated [3H]thymidine incorporation into chick embryo fibroblasts demonstrating that the cells released mitogen(s) into the medium. There was also a simultaneous release of insulin-like growth factor I (IGF-I) immunoreactivity into the medium. Acid chromatography of freeze-dried extracts of conditioned media by high performance gel permeation chromatography demonstrated that IGF-I immunoreactivity eluted in a major peak with a molecular weight of 7500 Da and a minor peak with a molecular weight of 55,000 Da. The release of IGF-I immunoreactivity was increased by pituitary-derived chicken growth hormone (cGH) in a dose-dependent manner with half-maximum stimulation occurring at a cGH concentration of 40 ng/ml and maximum stimulation at cGH concentrations greater than 800 ng/ml. These results demonstrate that cultured chicken hepatocytes produce IGF-I and that this can be stimulated by cGH in vitro.
O'Neill
I E
IE
Department of Molecular Endocrinology, AFRC Institute of Animal Physiology and Genetics Research, Edinburgh Research Station, Roslin, Midlothian, U.K.
Houston
B
B
Goddard
C
C
D000818:Animals; D002478:Cells, Cultured; D002642:Chick Embryo; D002850:Chromatography, Gel; D003470:Culture Media; D013006:Growth Hormone / Q000494:pharmacology*; D007334:Insulin-Like Growth Factor I / Q000096:biosynthesis*; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D008934:Mitogens / Q000378:metabolism; D008970:Molecular Weight; D013002:Somatomedins / Q000096:biosynthesis*; D013936:Thymidine / Q000378:metabolism
D003470:Culture Media; D008934:Mitogens; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D013936:Thymidine