Project progress

Longitudinal Analysis - Lifespans

From the end of 2004, about 32 mice/sex for each strain were entered into longitudinal study. One year later, another cohort of about 32 females was added for each strain to strengthen the statistic power. The most important measurement in this study is  the lifespans. In total, we included about 32 males and 64 females of each strain, 3744 mice in total. By end of March 2008, 609 mice are still alive.

Longitudinal Analysis – Non-invasive parameters

To characterize the features of aging process, we have measured many non-invasive parameters that were repeated at 6-months interval. They include: body weight, kidney function (blood urea nitrogen and urinary albumin, creatinine), liver function (ALT, albumin and total bilirubin), immunological function; and neuromuscular degeneration (using automated gait analysis and forelimb grip strength measurements).  Other phenotypes to be characterized are those that might change with age such as sleep patterns, food and water consumption, respiratory exchange ratios, and rest/activity patterns (using the comprehensive laboratory animal monitor system); anemias, platelet and white blood cell counts, routine clinical chemistries, and the metabolic syndrome (leptin, obesity, and glucose). These phenotypes/parameters have been measured longitudinally when the mice are 6-, 12-, 18- and 24-month old. All the 6, 12 and 18 months tests have been completed. The 24-months study will be finished in the following months.

Cross-sectional Analysis

To study the pathological effects of aging, we have set up 3 cohorts of mice (15 female and 15 male/strain/cohort). When mice were 6, 12 and 20 months old, we measured their heart function (EKG), body composition, bone density (DEXA), chromosome instability and DNA repair. For 6, 12 and 20-month cohorts, 545, 743 and 580 mice have been tested.