Misuse of androgenic-anabolic steroids and human deltoid muscle fibers: differences between polydrug regimens and single drug administration

Abstract

The objective of this investigation was to study the effects of androgenic-anabolic steroid (AAS) misuse on deltoid muscle fiber characteristics in experienced, male strength-trained athletes. In a double-blind study, 15 volunteers were administered nandrolone decanoate (ND) for 8 weeks (200 mg/week, intramuscularly). In an additional study, 12 subjects self-administered various AASs at supratherapeutic dosages (AAS group), while 7 non-users served as controls. In all subjects, a percutaneous needle biopsy sample of the deltoid muscle was obtained at baseline and after 8 weeks. Muscle sections were pre-incubated at pH 4.4, stained with adenosine triphosphatase and analyzed morphometrically. In each biopsy sample, at least 150 fibers were classified for "gray level" and "lesser fiber diameter" to determine the mean fiber size, the sizes of type I and type II fibers, and the fiber type distribution. ND administration did not seem to affect any of those parameters. In the AAS group, mean muscle fiber size (+ 12.6%), and the size of type I (+ 10.8%) and type II (+ 14.6%) muscle fibers increased. The fiber type distribution remained unaltered. We conclude that polydrug regimens of AAS misuse at supratherapeutic dosages increased the size of deltoid muscle fibers (especially type II fibers) in experienced strength-trained athletes, while ND at a therapeutic intramuscular dose of 200 mg did not exert any effect.

Subcellular effects of myocyte-specific androgen receptor overexpression in mice

“…Androgen-mediated increases in muscle mass in humans are associated with increased muscle fiber diameter (Marin et al 1992, Hartgens et al 2002, Ustunel et al 2003. However, in laboratory mice and rats, we do not typically see alterations in myofiber size in limb muscles following androgen manipulations (Monks et al 2004, Johansen et al 2009, although perineal muscles such as the levator ani do show marked reductions in myofiber size following androgen deprivation (Monks et al 2004, which is associated with myofibril disassembly (Venable 1966).…”

Efeitos dos hormônios anabólicos sobre a estrutura, metabolismo e função do músculo esquelético

“…Outra limitação é que, pela natureza do desenho experimental, há uma combinação de diversas drogas e dosagens. Hartgens et al (2002) 14 verificaram o efeito da utilização isolada de 200 mg/semana de nandrolona e de um "coquetel" auto-administrado com dosagem supraterapêuti-ca, num período de oito semanas. Enquanto não houve aumento na AST das fibras do grupo com nandrolona, um aumento médio de 12,6% (10,8% para tipo I e 14,6% para tipo II) foi observado no grupo que auto-administrou o coquetel.…”

The actions and side effects of Anabolic Steroids in sport and social abuse

“…The effect of AS on the human deltoid muscle, has been localised to an increase in size in the Type II muscle fibres [31] and this complements earlier studies showing that, at least in mammals, testosterone differentially increases the size of slow twitch rather than fast twitch muscles [42,66]. As a generalisation, testosterone and therefore, probably all anabolic steroids, increase upper body muscle power more than lower body power, and increase maximal voluntary strength and leg power but have little effect on muscle fatigability or muscle tension [70].…”