Submitted to: Meeting Abstract
Publication Type: Abstract only
Publication Acceptance Date: 9/1/2007
Publication Date: 10/1/2007
Citation: Fiorotto, M.L., Lopez, R., Rosenberger, R., Davis, T.A., Gomez, A.J. Malphus, E.W. 2007. Inadequate satellite cell replication compromises muscle regrowth following postnatal nutrient restriction [abstract]. 5th International Congress on Developmental Origins of Health and Disease, November 6-10, 2007, Perth, Western Australia. 83(Suppl. 1):S58[Abstract #2E-6]. Interpretive Summary:
Technical Abstract: Perinatal growth impairment permanently compromises skeletal muscle mass. The present study assessed the contribution of muscle satellite cell replicative capacity to this deficit. Mouse dams were fed either a low protein (LP, n=7) or control (C, n=6) diet during lactation. Pups were weaned at 21 d of age and fed diet C ad libitum. Quadriceps muscles were collected for analysis 0 and 14 d postweaning. In addition to muscle weights, muscle fiber cross-sectional area (xsa), and myonuclear and satellite cell (Pax7+ cells) numbers were quantified using immunohistochemical techniques. At weaning, LP muscles weighed 80% of control values (P<0.001), and was reflected by the average fiber xsa. Upon refeeding, muscle mass gain accelerated to age-appropriate levels, and remained proportionately smaller than C muscles. LP muscles contained fewer myonuclei per fiber than C (P<0.001) at weaning and after 14 d of refeeding (P<0.01). At 21 d of age the mean fiber xsa/myonucleus was not different between LP and C muscles but after 14 d of refeeding was higher for the LP group (P<0.03). LP muscles contained 30% fewer Pax+ cells per fiber (P<0.02) and this did not change upon refeeding. Following a reduction in muscle growth during the suckling period, the acceleration in growth rate upon refeeding was not sufficient to restore muscle mass. This impediment to muscle growth upon refeeding was likely due to a limited increase in myonuclear number that resulted from an impaired capacity of the existing satellite cells to proliferate.