Premium
In Utero Glucocorticoid (GLC) Exposure Reduces Fetal Skeletal Muscle Growth in Rats
Author(s) -
Gokulakrishnan Ganga,
Estrada Irma J,
Sosa Horacio A,
Fiorotto Marta L
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.740.3
Subject(s) - fetus , medicine , in utero , endocrinology , skeletal muscle , glucocorticoid , gestation , biology , pregnancy , genetics
Maternal undernutrition and stress expose the fetus to above normal levels of GLC and predispose to intrauterine growth restriction. The aim of this study was to determine if fetal GLC exposure impairs skeletal muscle growth independently of maternal undernutrition. Three groups (n=7/group) of timed‐pregnant Sprague‐Dawley rats were studied: Control (CON): ad libitum food intake. DEX: ad libitum food intake, oral DEX from embryonic day (ED) 13 to 21. Pair‐fed (PF): pair‐fed to DEX. On ED 22 (term), prior to surgical delivery, in vivo fractional protein synthesis rates (FSR) and total protein content of the fetal quadriceps and diaphragm muscles were measured. RESULTS DEX treatment (89 ± 6 μg/(kg.d)) reduced maternal food intake by 13% (P<0.001) and weight gain by 82% (P<0.001). DEX and PF muscle protein masses were 60% and 80% of CON respectively (P<0.01). Protein FSR was decreased by 35% in DEX fetuses (P<0.001), whereas protein FSR in PF muscles were the same as CON. CONCLUSIONS A modest reduction in maternal food intake impaired muscle growth. Reduced maternal food intake combined with GLC exposure exacerbated the effects on muscle growth. This can be explained by the effects of GLC on rates of fetal muscle protein synthesis combined with the effects of maternal food restriction on fetal muscle protein degradation. Supported by USDA/ARS grant no. 58‐6250‐6‐001 and NIH AR‐46308 Grant Funding Source : Supported by USDA/ARS grant no. 58‐6250‐6‐001 and NIH AR‐46308