Aging and restriction of dietary calories increases insulin receptor mRNA, and aging increases glucocorticoid receptor mRNA in the liver of female C3B10RF1 mice.
We investigated the influence of age and a 20% or 52% reduction in dietary calories (caloric restriction) on expression of mRNA for a number of transcription factors and signal-transducing proteins using 4, 16, and 30-month-old female mice of the long-lived C3B10RF1 strain. In all age groups, 52% caloric restriction, which extends maximum life span by approximately 33%, increased insulin receptor mRNA by 15% to 25% over the levels in animals fed ad libitum. Aging increased insulin receptor mRNA and glucocorticoid-receptor mRNA in all dietary groups. A similar increase in glucocorticoid receptor mRNA was not observed for male mice of three other strains, suggesting the change is sex- or strain-specific and not a general feature of aging. These changes appear to be specific. Neither caloric restriction nor age had an effect on the level of mRNA for insulin-like growth factor-I, RNA polymerase II elongation-factor S-II, or transcription factors Sp1, CCAAT and enhancer binding protein, or proto-oncogene c-jun.
Department of Biochemistry, University of California, Riverside.
S R
SR
Spindler
J M
JM
Grizzle
R L
RL
Walford
P L
PL
Mote
D000375:Aging / Q000378:metabolism*; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D015152:Blotting, Northern; D015342:DNA Probes; D004032:Diet; D002149:Energy Intake; D005260:Female; D015151:Immunoblotting; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D008099:Liver / Q000737:chemistry / Q000378:metabolism*; D008136:Longevity; D051379:Mice; D008815:Mice, Inbred Strains; D012333:RNA, Messenger / Q000032:analysis* / Q000235:genetics; D012335:RNA, Ribosomal / Q000032:analysis / Q000235:genetics; D011972:Receptor, Insulin / Q000235:genetics*; D011965:Receptors, Glucocorticoid / Q000235:genetics*; D014157:Transcription Factors / Q000032:analysis
D001786:Blood Glucose; D015342:DNA Probes; D012333:RNA, Messenger; D012335:RNA, Ribosomal; D011965:Receptors, Glucocorticoid; D014157:Transcription Factors; D007334:Insulin-Like Growth Factor I; D011972:Receptor, Insulin