Breeding of the Senescence Accelerated Mouse (SAM)

Abstract

Breeding and reproductive records were kept for SAM-R/1 and SAM-P/8, and their behavioral characteristics were investigated. The animals were cared for under conventional conditions in our Experimental Animal Facilities.
The results obtained were as follows.
1. We bred the two inbred sublines to the F-4 generation.
2. We found no significant difference in the gestation periods or litter sizes.
3. Differences were found in hair loss and lordokyphosis of the spine by visual inspection, palpation and soft X-rays.
4. The life span of the SAM-P/8//ODU was the shorter.
5. Step down latency, as measured by the step-down passive avoidance response, was shorter at 20 weeks in the SAM-P/8//ODU.
These results indicate that mice of the two sublines, SAM-R/1//ODU and SAM-P/8//ODU, keep their essential characteristics and can be used as stable murine models.