Metabolic profiles of rats of different ages.

Urine samples from 6- to 31-month-old male Fischer F344 rats were analyzed using a high performance liquid chromatograph and a unique computer-based data analysis and quality control system in order to discover substances that could be used as markers in the aging process. Metabolic profiles of the organic acids from these urines yielded 42 peaks whose areas could be measured reliably. Of the 42 peaks, 10 were found by analysis of variance to vary significantly (p less than 0.05) with age. Rats from the four ages could also be distinguished using a multivariate statistic (discriminant analysis).