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Journal of Aging Research
Volume 2011 (2011), Article ID 315640, 10 pages
http://dx.doi.org/10.4061/2011/315640
Research Article

Lifespan and Glucose Metabolism in Insulin Receptor Mutant Mice

1Molecular Gerontology, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo 173-0015, Japan
2Applied Biological Chemistry, United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo 183-8509, Japan
3Department of Aging Control Medicine, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-0033, Japan

Received 13 February 2011; Revised 15 April 2011; Accepted 19 May 2011

Academic Editor: Christian Sell

Copyright © 2011 Takahiko Shimizu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Insulin/insulin-like growth factor type 1 signaling regulates lifespan and resistance to oxidative stress in worms, flies, and mammals. In a previous study, we revealed that insulin receptor (IR) mutant mice, which carry a homologous mutation found in the long-lived daf-2 mutant of Caenorhabditis elegans, showed enhanced resistance to oxidative stress cooperatively modulated by sex hormones and dietary signals (Baba et al., (2005)). We herein investigated the lifespan of IR mutant mice to evaluate the biological significance of insulin signaling in mice. Under normoxia, mutant male mice had a lifespan comparable to that of wild-type male mice. IR mutant female mice also showed a lifespan similar to that of wild-type female mice, in spite of the fact that the IR mutant female mice acquired more resistance to oxidative stress than IR mutant male mice. On the other hand, IR mutant male and female mice both showed insulin resistance with hyperinsulinemia, but they did not develop hyperglycemia throughout their entire lifespan. These data indicate that the IR mutation does not impact the lifespan in mice, thus suggesting that insulin signaling might have a limited effect on the lifespan of mice.