Lifespan and Glucose Metabolism in Insulin Receptor Mutant Mice

Figure 4

Adiposity, bone density, food intake, reproduction, rectal temperature, and respiratory quotients of the 𝐼𝑟^P1195L/wt mice. (a) Both male and female 𝐼𝑟^P1195L/wt mice showed a significantly decreased fat ratio compared to 𝐼𝑟^wt/wt mice at 20 months of age. (b) Both male and female 𝐼𝑟^P1195L/wt mice showed significantly increased bone density compared to the 𝐼𝑟^wt/wt mice at 20 months of age. Aged 𝐼𝑟^P1195L/wt male (𝑛=6), 𝐼𝑟^P1195L/wt female (𝑛=6), 𝐼𝑟^wt/wt male (𝑛=6), and 𝐼𝑟^wt/wt female (𝑛=5) mice were evaluated by DEXA. (c) The food intake of 𝐼𝑟^P1195L/wt male and 𝐼𝑟^wt/wt male mice at 4, 11, and 17 months of age. No significant difference was observed between the food consumption by 𝐼𝑟^P1195L/wt (𝑛=10) and 𝐼𝑟^wt/wt (𝑛=12) mice. (d) The reproduction rate of 𝐼𝑟^P1195L/wt female mice. No significant difference was observed between 𝐼𝑟^P1195L/wt and 𝐼𝑟^wt/wt mice (at least 3 mice per genotype). (e) The rectal temperatures of 𝐼𝑟^P1195L/wt and 𝐼𝑟^wt/wt mice at 4 months of age. No significant differences were observed in the temperatures between the 𝐼𝑟^P1195L/wt and 𝐼𝑟^wt/wt mice (𝑛=4 for each genotype). *𝑃<0.05, **𝑃<0.005 by Student’s 𝑡-test. (f) The mean time course of respiratory quotients (RQ = VCO₂/VO₂) of male mice at 5 months of age. The values represent the mean of 24 hours of measurements from each animal (𝑛=3, male). *𝑃<0.05 by Student’s 𝑡-test.

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