title: Estrogen modulates the dimensions of the lung's gas-exchange surface area and alveoli in female rats.
abstract: Sexually mature virgin female rats and mice have a higher mass-specific gas-exchange surface area (Sa) and smaller alveoli than same-aged males even though mass-specific oxygen consumption (VO2) is the same, within species, in both sexes (G. D. Massaro, J. P. Mortola, and D. Massaro. Proc. Natl. Acad. Sci. USA 92: 1105-1107, 1995). We now report that rats subjected to ovariectomy at age 21 days had, at age 59 days, a smaller mass-specific Sa and larger alveoli than sham-ovariectomized rats; these differences were not due to differences in VO2 and were prevented by estrogen therapy. Furthermore, sham-ovariectomized rats treated with estrogen had smaller and more alveoli than sham-operated females not given estrogen. Androgenization of newborn female rats did not alter mass-specific Sa or alveolar size. Male mice genetically deficient in androgen receptors had the same mass-specific Sa as normal male littermates. We conclude that estrogen is responsible for the sexual dimorphism of the lung's gas-exchange region and induces the formation of smaller, more numerous alveoli in otherwise untreated female rats.
authors.affiliation: Lung Biology Laboratory, Georgetown University School of Medicine, Washington, District of Columbia 20007, USA.
authors.forename: G D
authors.initials: GD
authors.lastname: Massaro
authors.forename: J P
authors.initials: JP
authors.lastname: Mortola
authors.forename: D
authors.initials: D
authors.lastname: Massaro
mesh_terms: D000818:Animals; D004967:Estrogens / Q000494:pharmacology / Q000502:physiology*; D005260:Female; D005262:Feminization / Q000235:genetics / Q000503:physiopathology; D008168:Lung / Q000187:drug effects / Q000502:physiology* / Q000503:physiopathology; D008297:Male; D051379:Mice; D010052:Ovariectomy; D011650:Pulmonary Alveoli / Q000187:drug effects / Q000502:physiology* / Q000503:physiopathology; D011659:Pulmonary Gas Exchange / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012727:Sex Characteristics; D013739:Testosterone; D014770:Virilism / Q000139:chemically induced / Q000503:physiopathology
chemical_list: D004967:Estrogens; D013739:Testosterone