A group of five parameters as a new biological marker on F344/N rats

The National Institute for Longevity Sciences (NILS) established an aging f arm (A/F) for producing aging/aged laboratory rodents at the Experimental A nimal Facility Wing under the NILS A/F Guide planned by the Laboratory Anim al Research Facilities (LARF). Five parameters, the average life span, the number of days of 75, 50, and 25% survival points, and average of the top 1 0 longest life span among laboratory strains of rodents at NILS-A/F, were r eproducible for F344/N rats specifically by strain and sex under the LARF A /F guide. These five parameters may serve as an effective and practical bio logical marker, especially in aging science including longevity science, to evaluate characteristics of strains of laboratory rodents. The five parame ters can identify clear substrain differences between F344/N and F344/Du an d bleeder differences between F344/DuCrj and F344/DuCrl. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.