PATHOLOGICAL CHARACTERIZATION OF MALE WISTAR RATS FROM THE GERONTOLOGY RESEARCH-CENTER

Male Wistar rats aged 6-26 months were obtained from the colony of The Gerontology Research Center of the National Institute on Aging, and p athological profiles were assessed. One hundred animals were sacrifice d at 6, 12, 18, 21, 24, and 26 months and used for cross-sectional det erminations; also, 150 animals were followed longitudinally and sacrif iced when clinical signs of moribundity appeared. Renal disease contri buted the most common pathology observed in both studies (found in ove r 70% of the animals examined), with neoplasms a secondary problem (pi tuitary tumors were by far the most prevalent, with adenomas present i n almost-equal-to 20% of the animals). This analysis represents the fi rst complete pathological characterization of this commonly used rat m odel for aging research, and offers an opportunity for comparison with other rat strains.