Longevity and aging of mice from lines divergently selected for body weight for over 90 generations

We have analysed the differences between longevity and aging process in two Lines of mice selected divergently for body weight. As a result of long-te rm selection, the mice from two lines varied significantly in body weight d uring their life span. The differences regarded maturation rate, the length of the life time, reproduction performance, and fertility. Females from th e light line (L) were fertile for a longer period of time than those from t he heavy line (C), while the process of spermatogenesis disappearance start ed earlier in the light males than in the heavy ones. There were also diffe rences in the relative weight of adrenal glands and histopathological chang es connected with the hyperplasia of their spindle cells. The adrenal gland s in females from both lines were heavier than in males. A significantly hi gher percentage of the cortex cell hyperplasia was observed in adrenals of mice from the C line than the L line. The differences were also scored betw een mice from the selection lines in relation to the length of their life. On average, the L mice lived 30 days longer than the heavy ones. Body weigh t loss was observed earlier in the old heavy males than the L ones and this was correlated with the earlier mortality in this group of animals.