Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 5, 2001
Publication Date: N/A
Interpretive Summary: An understanding of the hormonal regulation of embryonic and post hatch muscle development and growth is important to enhancing poultry meat production. There is a lack of information on the factors involved in muscle differentiation during embryonic development. This study was conducted to evaluate the effect of several insulin-like growth factors and dtheir analogs on turkey satellite cell and embryonic myoblast proliferation. The results showed that in general the IGF analogs are less potent in stimulating muscle cell growth compared to their native IGF counterparts. These results will provide other scientists with information on the use of growth factors in cell culture in studies designed to study muscle development.
The effect of several human and chicken insulin-like growth factor (IGF) analogs on turkey satellite cell and embryonic myoblast proliferation was examined in serum-free medium. Similar rates of proliferation were seen when human or chicken IGF-I or IGF-II were administered to satellite cells. The biopotency of two analogs, which were modified to prevent interaction with IGF binding proteins, was also examined. Human Des(1-6)IGF-II was equipotent to both native human and chicken IGF-II. However, the chicken LR3 IGF-I analog was significantly less active toward satellite cells and embryonic myoblasts compared with chicken IGF-I. Human Leu27 IGF-II, an analog designed to have reduced affinity to the IGF Type I receptor, but unaltered binding to IGF binding proteins, had a diminished effect on cell proliferation. Examination of IGF receptor binding characteristics revealed that chicken LR3 IGF-I had reduced ability to compete with labeled dhuman IGF-I for binding to satellite cells or embryonic myoblasts compared with chicken IGF-I. The observed biological responses to IGFs suggest IGF binding proteins have little effect on Type I IGF receptor action in these cell types in serum-free medium. The results also suggest that alterations of the IGF molecule to prevent interaction with binding proteins may also alter receptor binding affinity.