[Discriminant analysis of age parameters of the rat (author's transl)]

The capacity of age parameters to discriminate between groups or individuals of different biological age was investigated in the course of a long-term cohort study. 23 age parameters measured in 71 male Sprague-Dawley rats at the ages of 10, 17, 25 and 30 months, were submitted to a stepwise discriminant analysis. An optimal simultaneous discrimination between the four age groups was obtained by 3 discriminant functions with scores of 89.8%, 6.2% and 4%, with a correct classification of 98,6% of all individuals. Three analyses of successive age groups (10--17, 17--25, 25--30 months) resulted in a 100% correct classification by one function each. However, it turned out that in different phases of senescence an optimal discrimination between individuals or groups of different biological age is obtained by distinct combinations and weights of the parameters.