Effects of Anabolic Steroids and High-Intensity Aerobic Exercise on Skeletal Muscle of Transgenic Mice

Author(s)

Fontana, Karina ^{[1, 2]} ; Campos, Gerson E. R. ^[3] ; Staron, Robert S. ^[4] ; da Cruz-Hoefling, Maria Alice ^[2]

Affiliation

^[1] Univ Estadual Campinas, Fac Med Sci, Dept Pharmacol, Campinas - Brazil

^[2] Univ Estadual Campinas, Inst Biol, Dept Histol & Embryol, Campinas - Brazil

^[3] Univ Estadual Campinas, Inst Biol, Dept Biol Estrutural & Func, Campinas - Brazil

^[4] Ohio Univ, Dept Biomed Sci, Heritage Coll Osteopath Med, Athens, OH 45701 - USA

• Document type: Journal article
• Source: PLoS One; v. 8, n. 11 NOV 15 2013.
• Web of Science Citations: 6

Abstract

In an attempt to shorten recovery time and improve performance, strength and endurance athletes occasionally turn to the illicit use of anabolic-androgenic steroids (AAS). This study evaluated the effects of AAS treatment on the muscle mass and phenotypic characteristics of transgenic mice subjected to a high-intensity, aerobic training program (5d/wk for 6 weeks). The transgenic mice (CETP+/-LDLr-/+) were engineered to exhibit a lipid profile closer to humans. Animals were divided into groups of sedentary (Sed) and/or training (Ex) mice (each treated orally with AAS or gum arabic/vehicle: Sed-C, Sed-M, ex-C, ex-M). The effects of AAS (mesterolone: M) on specific phenotypic adaptations (muscle wet weight, cross-sectional area, and fiber type composition) in three hindlimb muscles (soleus: SOL, tibialis anterior: TA and gastrocnemius: GAS) were assessed. In order to detect subtle changes in fiber type profile, the entire range of fiber types (I, IC, IIAC, IIA, IIAD, IID, IIDB, IIB) was delineated using mATPase histochemistry. Body weight gain occurred throughout the study for all groups. However, the body weight gain was significantly minimized with exercise. This effect was blunted with mesterolone treatment. Both AAS treatment (Sed-M) and high-intensity, aerobic training (ex-C) increased the wet weights of all three muscles and induced differential hypertrophy of pure and hybrid fibers. Combination of AAS and training (ex-M) resulted in enhanced hypertrophy. In the SOL, mesterolone treatment (Sed-M and ex-M) caused dramatic increases in the percentages of fiber types IC, IIAC, IIAD, IID, with concomitant decrease in IIA, but had minimal impact on fiber type percentages in the predominantly fast muscles. Overall, the AAS-induced differential adaptive changes amounted to significant fiber type transformations in the fast-to-slow direction in SOL. AAS treatment had a significant effect on muscle weights and fiber type composition in SOL, TA and GAS which was even maximized in animals subjected to metabolically high-intensity aerobic exercise. (AU)