title: Gastrocnemius mitochondrial respiration: are there any differences between men and women?
abstract: BACKGROUND
  Work on human and mouse skeletal muscle by our group and others has demonstrated that aging and age-related degenerative diseases are associated with mitochondrial dysfunction, which may be more prevalent in males. There have been, however, no studies that specifically examine the influence of male or female sex on human skeletal muscle mitochondrial respiration. The purpose of this study was to compare mitochondrial respiration in the gastrocnemius of adult men and women.
  
  
  METHODS
  Gastrocnemius muscle was obtained from male (n = 19) and female (n = 11) human subjects with healthy lower-extremity musculoskeletal and arterial systems and normal ambulatory function. All patients were undergoing operations for the treatment of varicose veins in their legs. Mitochondrial respiration was determined with a Clark electrode in an oxygraph cell containing saponin-skinned muscle bundles. Complex I-, II-, III-, and IV-dependent respiration was measured individually and normalized to muscle weight, total protein content, and citrate synthase (CS, index of mitochondrial content).
  
  
  RESULTS
  Male and female patients had no evidence of musculoskeletal or arterial disease and did not differ with regard to age, race, body mass index, or other clinical characteristics. Complex I-, II-, III-, and IV-dependent respiration normalized to muscle weight, total protein content, and CS did not statistically differ for males compared with females.
  
  
  CONCLUSIONS
  Our study evaluates, for the first time, gastrocnemius mitochondrial respiration of adult men and women who have healthy musculoskeletal and arterial systems and normal ambulatory function. Our data demonstrate there are no differences in the respiration of gastrocnemius mitochondria between men and women.
authors.affiliation: Department of Surgery, University of Nebraska Medical Center, Omaha, Nebraska.
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Thompson
authors.forename: Stanley A
authors.initials: SA
authors.lastname: Swanson
authors.forename: George P
authors.initials: GP
authors.lastname: Casale
authors.forename: Jason M
authors.initials: JM
authors.lastname: Johanning
authors.forename: Evlampia
authors.initials: E
authors.lastname: Papoutsi
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Koutakis
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Miserlis
authors.forename: Zhen
authors.initials: Z
authors.lastname: Zhu
authors.forename: Iraklis I
authors.initials: II
authors.lastname: Pipinos
mesh_terms: D000375:Aging / Q000378:metabolism*; D019069:Cell Respiration / Q000502:physiology; D004579:Electron Transport / Q000502:physiology; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D008928:Mitochondria / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000166:cytology / Q000378:metabolism*; D009210:Myofibrils / Q000502:physiology; D010101:Oxygen Consumption / Q000502:physiology; D011048:Polarography; D012727:Sex Characteristics
keywords: Gastrocnemius; Mitochondria; Polarography; Respiration; Sex; Skeletal muscle