Effect of administration of oral contraceptives on the synthesis and breakdown of myofibrillar proteins in young women

M Hansen, H. Langberg, Lars Holm, B F Miller, S.G. Petersen, Simon Doessing, D Skovgaard, T. Trappe, Michael Kjær

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38 Citations (Scopus)

Abstract

Oral contraceptive (OC) treatment has an inhibiting effect on protein synthesis in tendon and muscle connective tissue. We aimed to investigate whether OC influence myofibrillar protein turnover in young women. OC-users (24±2 years; Lindynette® n=7, Cilest® n=4) and non-OC-users (controls, 24±4 years n=12) performed one-legged kicking exercise. The next day, the myofibrillar protein fractional synthesis rate (FSR) was measured using stable isotopic tracers ((13)C-proline) while the subjects were fed standardized nutrient drinks. Simultaneously, a marker for myofibrillar protein breakdown, 3-methyl-histidine (3-MH), was measured in the interstitial fluid of the vastus lateralis. Measurements were performed in both legs. In general, myofibrillar protein FSR was lower in OC-users (two-way analysis of variance, P<0.05), although the difference seemed to depend on the OC type. Interstitial 3-MH in the skeletal muscle was not different between groups and did not vary by OC type. Exercise did not change myofibrillar protein FSR or 3-MH concentrations. Serum androstenedione and bioavailability of testosterone were lower in OC-users. In conclusion, the results indicate that the use of OC has an inhibiting effect on myofibrillar protein synthesis and the magnitude of the effect may depend on the type of OC. In contrast, there was no effect of OC on myofibrillar protein breakdown in the fed state.
Original languageEnglish
JournalScandinavian Journal of Medicine & Science in Sports
Volume21
Issue number1
Pages (from-to)62-72
Number of pages11
ISSN0905-7188
DOIs
Publication statusPublished - 2011

Keywords

  • Analysis of Variance
  • Contraceptives, Oral
  • Energy Intake
  • Exercise Test
  • Female
  • Humans
  • Leg
  • Methylhistidines
  • Muscle Proteins
  • Muscle, Skeletal
  • Myofibrils
  • Proline
  • Young Adult

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