title: Effect of sex steroids on soleus muscle response in hypocalcemic medium (in vitro).
abstract: OBJECTIVE
  Postoperative hypocalcemia is a frequently encountered complication of thyroid surgery. Since hypocalcemic symptoms are closely associated with sex, the aim of this study is to investigate the effects of sex steroids on muscle tissue under hypocalcemic conditions.
  
  
  METHODS
  Six groups consisting of control male (M), control female (F), gonadectomized male (M-), gonadectomized female (F-), estradiol-applied gonadectomized male (MX), and testosterone-applied gonadectomized female (FX) rats were used. Contraction recordings were obtained from soleus muscle flaps. Maximal tension (PT), frequency required for 50% of PT (F50), contraction velocity at F50 (V50), and changes in contraction values (d[PT], d[F50], d[V50]) between normocalcemic and hypocalcemic conditions were calculated.
  
  
  RESULTS
  d[PT], d[F50], and d[V50] were significantly higher in M- and MX groups compared with control M group. Whereas d[PT], d[F50], and d[V50] parameters of the F- group were significantly higher than control F group, d[F50] and d[PT] of the FX group showed no significant change and d[V50] for the FX group was significantly lower. A comparison of control groups showed that d[PT], d[F50], and d[V50] of the F group were significantly higher than those of the M group.
  
  
  CONCLUSIONS
  Whereas absence of both testosterone and estradiol caused an increase in hypocalcemia-induced changes in contraction parameters of rat skeletal muscle, presence or application of testosterone clearly stabilized contraction parameters.
authors.affiliation: Department of General Surgery, Konya Teaching and Research Hospital, Konya, Turkey. Electronic address: skokcam@gmail.com.
authors.forename: S Said
authors.initials: SS
authors.lastname: Kökçam
authors.forename: Şakir
authors.initials: Ş
authors.lastname: Tekin
authors.forename: Adil
authors.initials: A
authors.lastname: Kartal
authors.forename: Murat
authors.initials: M
authors.lastname: Ayaz
authors.forename: Mustafa
authors.initials: M
authors.lastname: Şahin
authors.forename: Fahreddin
authors.initials: F
authors.lastname: Acar
authors.forename: Murat
authors.initials: M
authors.lastname: Çakir
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Küçükbağriaçik
mesh_terms: D000728:Androgens / Q000097:blood / Q000172:deficiency / Q000494:pharmacology; D000818:Animals; D004958:Estradiol / Q000097:blood / Q000172:deficiency* / Q000494:pharmacology; D004967:Estrogens / Q000097:blood / Q000172:deficiency / Q000494:pharmacology; D005260:Female; D006996:Hypocalcemia / Q000209:etiology / Q000378:metabolism*; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology*; D009919:Orchiectomy; D010052:Ovariectomy; D011183:Postoperative Complications / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012737:Sex Factors; D013739:Testosterone / Q000097:blood / Q000172:deficiency* / Q000494:pharmacology; D013965:Thyroidectomy / Q000009:adverse effects
chemical_list: D000728:Androgens; D004967:Estrogens; D013739:Testosterone; D004958:Estradiol
keywords: Estradiol; Gender; Hypocalcemia; Skeletal muscle; Soleus; Testosterone