title: Hormone-treated snell dwarf mice regain fertility but remain long lived and disease resistant.
abstract: Snell dwarf mice have multiple hormonal deficits, but the way in which these deficits postpone aging are still uncertain. In this study, Snell dwarf mice received 11 weeks of growth hormone and thyroxine injections that increased their weight by approximately 45%, although they remained much smaller than controls. The hormone treatment also restored fertility to male dwarf mice. Despite these effects on growth and maturation, the hormone treatments did not diminish life span or lower the resistance of dwarf mice to cataracts and kidney disease. Administration of thyroxine in food throughout adult life did diminish longevity of Snell dwarf mice, although these mice remain longer lived than control animals. These results show that a 45% increase in body size does not impair longevity or disease resistance for dwarf mice of either sex, and that the exceptional longevity of Snell dwarf mice does not, at least for males, depend on prepubertal immaturity.
authors.affiliation: Department of Pathology and Geriatrics Center, University of Michigan, Ann Arbor, MI 48109-0940, USA.
authors.forename: Maggie
authors.initials: M
authors.lastname: Vergara
authors.forename: Michael
authors.initials: M
authors.lastname: Smith-Wheelock
authors.forename: James M
authors.initials: JM
authors.lastname: Harper
authors.forename: Robert
authors.initials: R
authors.lastname: Sigler
authors.forename: Richard A
authors.initials: RA
authors.lastname: Miller
mesh_terms: D000818:Animals; D049628:Body Size; D004268:DNA-Binding Proteins / Q000235:genetics*; D004392:Dwarfism / Q000235:genetics / Q000503:physiopathology*; D005260:Female; D005298:Fertility; D006128:Growth / Q000187:drug effects; D013006:Growth Hormone / Q000494:pharmacology*; D007334:Insulin-Like Growth Factor I / Q000502:physiology; D008136:Longevity; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D008817:Mice, Mutant Strains; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000494:pharmacology*; D050817:Transcription Factor Pit-1; D014157:Transcription Factors / Q000235:genetics*
chemical_list: D004268:DNA-Binding Proteins; D013006:Growth Hormone; D007334:Insulin-Like Growth Factor I; D013972:Thyrotropin; D013974:Thyroxine; D050817:Transcription Factor Pit-1; D014157:Transcription Factors; C494185:Pou1f1 protein, mouse