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Mechanisms of Dietary Restriction in Aging and Disease
Effects of Dietary Restriction on the Expression of Insulin-Signaling-Related Genes in Long-Lived Mutant Mice
Bartke A, Masternak M, Al-Regaiey K, Bonkowski M
Mobbs CV, Yen K, Hof PR (eds): Mechanisms of Dietary Restriction in Aging and Disease.
Interdiscipl Top Gerontol. Basel, Karger, 2007, vol 35, pp 69-82 (DOI: 10.1159/000096556)
Abstract: Hypopituitary Ames dwarf mice and growth-hormone-resistant (growth hormone
receptor knockout, GHRKO) mice have reduced plasma levels of insulin-like growth factor 1
and insulin, enhanced insulin sensitivity and a remarkably increased life span. This resembles
the phenotypic characteristics of genetically normal animals subjected to dietary restriction
(DR). Interestingly, DR leads to further increases in insulin sensitivity and longevity in Ames
dwarfs but not in GHRKO mice. It was therefore of interest to examine the effects of DR on
the expression of insulin-related genes in these two types of long-lived mutant mice. The
effects of DR partially overlapped but did not duplicate the effects of Ames dwarfism or
GHR deletion on the expression of genes related to insulin signaling and cell responsiveness
to insulin. Moreover, the effects of DR on the expression of the examined genes in different
insulin target organs were not identical. Some of the insulin-related genes were similarly
affected by DR in both GHRKO and normal mice, some were affected only in GHRKO mice
and some only in normal animals. This last category is of particular interest since genes
affected in normal but not GHRKO mice may be related to mechanisms by which DR
extends longevity.
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© 2009 S. Karger AG, Basel
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