THE ROLE OF SEX AND GENOTYPE ON ANTIORTHOSTATIC SUSPENSION EFFECTS ONTHE MOUSE PERIPHERAL SKELETON

Previous antiorthostatic suspension studies have used a single sex and strain of rat or mouse. Nonetheless, broadly similar effects of suspe nsion on the two species indicates a generalized effect of suspension not attributed to specific genetic, behavioral, or sex-linked etiology . In order to directly test genetic and sex-linked factors, the effect s of suspension on the appendicular bone of male and female BALB-CJ, C 57BL-6J, and DBA-2J mice were compared. These genotypes were selected based on their widely different developmental and behavioral character istics as well as on past research involving a heterogeneous strain de rived from these strains. The effects of suspension on the geometric, mechanical, and material properties of the femora, humeri, and tibiae were determined. Among the bone types, the femora were most significan tly affected by suspension. The effects of suspension were similar in nature in male and female mice aged 1.7 months. Strain-dependent suspe nsion effects may be indicative of bone developmental differences in t he strains at the age chosen.