The effects of stress on cortical bone thickness in rodents

The right and left femora of three groups of rodents, cold stressed, noise stressed, and heat stressed, were sectioned transversely at the most inferior point of the third trochanter. Cortical bone thickness of the proximal section for all three groups was determined by measuring an enlargement obtained with a Wild stereo microscope with a camera lucida drawing attachment. Cold stressed animals were found to have significantly thinner cortical bone than did controls, noise stressed animals did not differ from controls, and heat stressed animals had thinner cortical bone than did controls. It is concluded that stress may be responsible for the thinner cortex of cold and heat stressed animals, but that other factors may be at work and that it is not possible to tell whether different types of stress act through the same or through different mechanisms.