Muscle function in monozygotic female twin pairs discordant for hormone replacement therapy
| Autor: | Noorkoiv M, Taija Finni, Paula H. A. Ronkainen, Kovanen, Sarianna Sipilä, Markku Alen, Jaakko Kaprio, Eija Pöllänen |
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| Jazyk: | angličtina |
| Rok vydání: | 2011 |
| Předmět: |
estradioli
medicine.medical_specialty genetic structures Physiology 030310 physiology Monozygotic twin Stimulation plantarflexor 03 medical and health sciences Cellular and Molecular Neuroscience Muscle nerve Sex hormone-binding globulin Physiology (medical) Internal medicine medicine Humans voima Muscle Strength twitch Muscle Skeletal väsyminen 030304 developmental biology 0303 health sciences Postmenopausal women biology Estradiol business.industry Electromyography Estrogen Replacement Therapy Skeletal muscle Twins Monozygotic Middle Aged estrogeeni Endocrinology medicine.anatomical_structure Transgender hormone therapy Muscle Fatigue biology.protein Time to peak fatigue Female sense organs Neurology (clinical) strength business human activities Muscle Contraction |
| Zdroj: | Muscle & Nerve Muscle & Nerve; Vol 44 |
| ISSN: | 0148-639X |
| DOI: | 10.1002/mus.22162 |
| Popis: | Introduction: Postmenopausal monozygotic twin pairs discordant for hormone replacement therapy (HRT) provide an advantageous study design controlling for genetic background for elucidating the relationships between aging, sex hormone levels, muscle strength, contractile capacity, and fatigability. Methods: Thirteen postmenopausal monozygotic twin pairs discordant for HRT were measured for maximal voluntary torque (MVC) and twitch characteristics using electrical stimulation before and after intermittent dynamic plantarflexor exercise until exhaustion. Results: Peak twitch torque was 32% higher in HRT users than in their non-HRT, genetically identical sisters (P = 0.002), but MVC did not differ. There were no differences in the activation level or twitch time characteristics between the co-twins. Fatigue caused decreases in MVC (P = 0.001), twitch torque (P = 0.001), time to peak (P = 0.013), and half-relaxation time (P = 0.001) similarly in HRT users and non–HRT users. Conclusion: In early postmenopausal women, involuntary but not voluntary force-generating mechanisms of the plantarflexors are augmented by the use of HRT. Muscle Nerve, 2011 |
| Databáze: | OpenAIRE |
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