title: Distribution and levels of insulin-like growth factor I mRNA across the life span in the Brown Norway x Fischer 344 rat brain.
abstract: Previous studies have reported changes in insulin-like growth factor I (IGF-I) mRNA expression during early postnatal development of the rat brain. Although changes in IGF-I gene expression have been documented in a wide range of central nervous system structures during early development and investigated in the hippocampus during aging, no study has compared changes in IGF-I gene expression in different brain regions across the life span. The present study assessed the distribution of IGF-I gene expression using in situ hybridization in rats aged 2-30 months. Dot blots were used as a quantitative assessment of cortical IGF-I mRNA. Results indicate that both the distribution and levels of brain IGF-I mRNA do not change significantly between 2 and 30 months of age in the rat. However, in spite of relatively constant levels of mRNA, other studies from our laboratory have demonstrated that cortical IGF-I protein levels decrease 36.6% between 11 and 32 months of age, suggesting that IGF-I function is decreased with increasing age.
authors.affiliation: Department of Neurobiology and Anatomy, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
authors.forename: M M
authors.initials: MM
authors.lastname: Niblock
authors.forename: J K
authors.initials: JK
authors.lastname: Brunso-Bechtold
authors.forename: C D
authors.initials: CD
authors.lastname: Lynch
authors.forename: R L
authors.initials: RL
authors.lastname: Ingram
authors.forename: T
authors.initials: T
authors.lastname: McShane
authors.forename: W E
authors.initials: WE
authors.lastname: Sonntag
mesh_terms: D000375:Aging / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000378:metabolism*; D006824:Hybridization, Genetic; D017403:In Situ Hybridization; D007334:Insulin-Like Growth Factor I / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D011914:Rats, Inbred BN; D011916:Rats, Inbred F344; D014018:Tissue Distribution
chemical_list: D012333:RNA, Messenger; D007334:Insulin-Like Growth Factor I