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Estrogen receptor (ER) α and β and Aromatase knock‐out (ArKO) effects on muscle development in male mice
Author(s) -
ferreira Andries Johan,
Lubahn Dennis B,
Brown Marybeth
Publication year - 2008
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.22.1_supplement.754.1
Subject(s) - endocrinology , medicine , estrogen receptor , aromatase , estrogen , chemistry , myosin , skeletal muscle , muscle contraction , biology , biochemistry , cancer , breast cancer
ERs have been identified in male muscle but whether estrogen (E2) exerts its effects through ERα or ERβ is unclear. Direct E2 effects on developing muscle were also determined in ArKO. All comparisons were made to corresponding wild type (WT) controls. Muscle mass, particularly in fast‐fibered gastrocnemius (Gast) and Tibialis Anterior (TA) (not soleus or plantaris) was diminished in ERα but not ERβ. Most absolute mass measures, and 3 of 4 muscles normalized to body weight were significantly lower in ArKO mice compared with WT. Normalized muscle mass/body weight was still lower in ERAα Gast and TA but not in the ERβ group. There was no difference between WT and KO mice in peak force, force/area, force/velocity, time to peak tension or ½ relaxation time. Total protein and contractile protein myosin in Gast and TA were similar in WT and KO, further indication that contractile function was not affected by KO status. Results suggest ERαKO and ArKO may directly regulate muscle growth without affecting contractile function. The presence or absence of ERβ does not alter skeletal muscle function in male mice. Estrogen may be required for complete muscle size during development. Support: Spinal Injuries Board, Research Board