Sobre

Taking Anabolic Steroids After A Sport Injury

Below is an overview that addresses the key questions you raised about anabolic‑steroid (AS) use in sports, with a brief discussion of mechanisms, performance‑related effects, evidence from controlled studies, and typical dosing ranges reported in the literature. The information is drawn from peer‑reviewed journals (mostly Sports Medicine, Medicine & Science in Sports & Exercise, Journal of Applied Physiology and related sources). Where possible I have included reference numbers that correspond to the bibliography at the end of this document.



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1. What are anabolic steroids?




Term Definition Key Pharmacological Feature


Anabolic–steroid (AS) Endogenous or synthetic compounds structurally related to testosterone, that bind to androgen receptors and stimulate protein synthesis, cell proliferation, and nitrogen retention in skeletal muscle. Strong affinity for androgen receptor; some possess 5α‑reductase activity (converted to dihydrotestosterone).


Synthetic derivatives Chemical modifications that enhance oral bioavailability or reduce metabolism (e.g., methylation at C17β). Methylated compounds are orally active but hepatotoxic.


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Mechanism of Action in Skeletal Muscle




Androgen Receptor Binding



- AS binds to intracellular androgen receptors → receptor‑ligand complex translocates to nucleus.
- Binds to DNA hormone response elements (HREs) → activates transcription of target genes.





Transcriptional Targets



Gene Function Effect on Muscle


IGF‑1 Growth factor Promotes satellite cell proliferation, hypertrophy.


Myogenin / MyoD Myogenic regulatory factors Drive differentiation of progenitor cells.


MHC (myosin heavy chain) Contractile protein Increase contractile force.


Atrogenes (MuRF1, MAFbx/atrogin‑1) Ubiquitin ligases Reduced expression → less proteolysis.





Post‑Translational Modifications




Phosphorylation of Akt → activates mTORC1.


Acetylation / Deacetylation (SIRT1) influences transcription factors.








4. Integrated Pathway Diagram (Textual)



Resistance Exercise
|
v
Mechanical Stress --> ↑ Intracellular Ca²⁺, ROS, AMP/ATP Ratio
| \
| \--> Activation of AMPK
| \
| --> Activation of MAPK (ERK1/2, p38)
| \
v \
Satellite Cell Activation --> Transcriptional Changes
| |
| v
+----> Myogenic Regulatory Factors (MyoD, Myf5) ----+
| |
| v
| ↑ Gene Expression of
| Structural Proteins
| (e.g., Titin)
| |
v v
Hypertrophy ---------------------------------> Protein Synthesis
| |
| v
+-------------------------------------------------+