The effects of audiogenic stress on the growth of long bones in the laboratory rat (Rattus norvegicus).

It has been demonstrated that experimentally induced cold stress produces a stunting effect in the limbs of rodents. Such an effect has also been reported for the dentition and limbs in response to other stressors (heat, cold). Recent research into the effects of various stressors on the magnitude of fluctuating dental asymmetry demonstrated that general stress increases the magnitude of fluctuating dental asymmetry in experimental animals. However, no increase in the magnitude of fluctuating asymmetry of limb length was reported as a response of general stress. In the light of such studies the present research investigates the relationship between stress and the mass per unit length of limbs. The stressor chosen for the present study was audiogenic stress as it has been demonstrated to induce the general stress syndrome and also increase the magnitude of fluctuating dental asymmetry. Audiogenic stress is found to produce increases in the magnitude of fluctuating asymmetry of the mass per unit length of long bones in the laboratory rat. Also the absolute values of long bone length and mass per unit length are significantly smaller in stressed animals when compared with controls. The relationship between the stress induced stunting of linear dimensions and the increase in the magnitude of fluctuating asymmetry is discussed.