Submitted to: Journal of Animal Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 10/16/2003
Publication Date: 2/1/2004
Citation: Hausman, G.J., Poulos, S.P. 2004. Recruitment and differentiation of intramuscular preadipocytes in stromal-vascular cell cultures derived form neonatal pig semitendinosus muscles. Journal of Animal Science. 2004. v. 82. p. 429-437. Interpretive Summary: Fat cells in muscle or marbling fat cells develop later than fat cells in back fat and recent studies indicate that it may be possible to decrease back fat cell development while increasing marbling fat cell development. Cell cultures were modified so the development of back fat and marbling fat cell precursors could be directly studied and compared under identical conditions. Conventional agents similarly increased back fat and marbling fat cell precursor development in cell culture. Cultures of back fat and marbling fat cell precursors can be used to screen for dietary supplements or growth promotants that differentially influence back fat and marbling fat cell development.
Technical Abstract: The present study examined the influence of dexamethasone (DEX) treatment on preadipocyte recruitment and expression of CCAAT/enhancing binding protein ' (CEBP') and peroxisome proliferator activated receptor- ' (PPAR ') proteins in stromal-vascular (SV) cell cultures derived from neonatal subcutaneous adipose tissue and semitendinosus muscles. Adipose tissue and muscles from 5-7 day-old pigs were pooled resulting in one muscle and one adipose SV cell culture established per pig. Conventional SV cell culture procedures were used to digest adipose and muscle tissue and harvest and culture adipose and muscle SV cells. One hour after seeding, muscle SV cell cultures were rinsed and refed new media to remove debri and insoluble muscle protein. S-V cell cultures were double stained for lipid and the AD-3 antibody, a preadipocyte marker, at 1, 3 and 6 days and double stained for lipid and CEBP' or PPAR' at day 6. In control media (no DEX), relative and absolute fat cell numbers were lower (P>.05) in muscle than in adipose S-V cell cultures. DEX treatment produced similar fold increases in relative and absolute preadipocytes and fat cells in muscle and adipose SV cultures but the absolute numbers of preadipocytes and fat cells were much less (P>.05) in muscle SV cell cultures. These studies indicate that muscle SV cultures are characterized by a low number of glucocorticoid responsive preadipocytes.