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Ethinyl estradiol suppress tendon collagen synthesis in response to exercise
Author(s) -
Hansen Mette,
Koskinen Satu,
Petersen Susanne Germann,
Dossing Simon,
Frystyk Jan,
Flyvbjerg Allan,
Kjaer Michael,
Langberg Henning
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.753.28
Subject(s) - tendon , microdialysis , endocrinology , medicine , bioavailability , rest (music) , chemistry , surgery , pharmacology , central nervous system
We aimed to investigate whether oral contraceptives (OC), resulting in enhanced circulating level of ethinyl‐estradiol, influences tendon collagen metabolism at rest and after exercise. Healthy young women, OC‐users (n=11) and control (n=12), were studied 24h following one‐legged kicking exercise (EX) for 60 min at 67 % of Wattmax. Microdialysis catheters were placed anterior to the patellar tendon of both legs, and interstitial fluid was collected and analyzed for the amino‐terminal propeptide of type I collagen (PINP), a marker of tendon collagen synthesis. An exercise‐induced increase in tendon synthesis was observed in control (PINP: Rest: 25.3 ± 11 (mean ± SD) ng ml −1 vs. EX: 48.3 ± 28 ng ml −1 , P < 0.05), but not in OC‐users (EX: 27.4 ± 16 ng ml −1 vs. Rest: 31.5 ± 20 ng ml −1 ). Insulin‐like growth factor I (IGF‐I) both in serum and in the interstitial tendon tissue fluid was significantly lower in OC‐users compared to control, whereas IGFBPs were significantly higher, which in combination with lower IGF‐I. In conclusion, OC seems to have an inhibiting effect on tendon synthesis in response to exercise either directly or indirectly by a reduction of the bioavailability of IGF‐I.