title: Expression of sex steroid hormone receptors in human skeletal muscle during the menstrual cycle.
abstract: Variations in sex hormone levels during the menstrual cycle may affect neuromuscular performance and the risk of sustaining musculoskeletal injury in women. The aim of this study was to investigate mRNA and protein levels for sex steroid hormone receptors in skeletal muscle in three distinct phases of the menstrual cycle.
  
  
  
  Fifteen, healthy women with regular menstrual cycles participated in the study. Muscle biopsies from the vastus lateralis were obtained in three hormonally verified phases of the menstrual cycle for each individual, that is the follicular phase, the ovulatory phase and the luteal phase. mRNA and protein levels of oestrogen (ERα and ERβ), progesterone (PR) and androgen (AR) receptors were analysed.
  
  
  
  There was an overall significant variation in mRNA and protein levels of ERα and PR across the menstrual cycle. mRNA and protein levels of ERα were highest in the follicular phase when oestradiol levels were low, whereas protein levels of PR were highest in the luteal phase when progesterone levels were high. mRNA levels of PR were highest in the ovulatory phase. No significant variation in AR levels was detected across the menstrual cycle. ERβ levels were very low in all three phases of the menstrual cycle.
  
  
  
  Significant variations in mRNA and protein levels of ERα and PR were detected in skeletal muscle during three confirmed phases of the menstrual cycle. These results may have an impact on effects of muscular training and sports injuries in women.
authors.affiliation: Division of Physiotherapy, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Huddinge, Sweden.
authors.forename: L
authors.initials: L
authors.lastname: Ekenros
authors.affiliation: Department of Biosciences and Nutrition, Karolinska Institutet, NOVUM, Huddinge, Sweden.|Centre for Clinical Research Sörmland, Uppsala University, Uppsala, Sweden.
authors.forename: Z
authors.initials: Z
authors.lastname: Papoutsi
authors.affiliation: Division of Physiotherapy, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Huddinge, Sweden.|Academic Primary Health Care Center, St Erik Primary Health Care Center, Stockholm, Sweden.
authors.forename: C
authors.initials: C
authors.lastname: Fridén
authors.affiliation: Department of Biosciences and Nutrition, Karolinska Institutet, NOVUM, Huddinge, Sweden.
authors.forename: K
authors.initials: K
authors.lastname: Dahlman Wright
authors.affiliation: Division of Obstetrics and Gynecology, Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Lindén Hirschberg
mesh_terms: D000328:Adult; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008597:Menstrual Cycle / Q000502:physiology*; D018482:Muscle, Skeletal / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D011944:Receptors, Androgen / Q000032:analysis / Q000096:biosynthesis*; D011960:Receptors, Estrogen / Q000032:analysis / Q000096:biosynthesis*; D011980:Receptors, Progesterone / Q000032:analysis / Q000096:biosynthesis*; D055815:Young Adult
chemical_list: D011944:Receptors, Androgen; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone
keywords: androgen receptor; oestrogen receptor-alpha; oestrogen receptor-beta; progesterone receptor; skeletal muscle