Abstract
The effects of exposure to noise and voluntary exercise on serum, liver and femur components were investigated in rats. Male Wistar rats (100-130g) were divided into three groups: non-noise and non-exercise (control) group, noise and non-exercise (N-NE) group, noise and exercise (N-E) group. All animals were fed a commercial diet (vitamin C-free CL-2: autaclaved at 121°C for 15 min) ad libitum for an experimental period of one, two or three weeks. The noise-forced rats were exposed to a noise of 3, 000Hz, 95 phone, for 8h per day. The exercise group was allowed voluntary exercise in a cage wheel equippied with a recorder. Urinary corticosterone excretion increased significantly in the N-NE group, but the value in the N-E group was as low as that in the control group. Ratio of urinary Ca excretion to Ca intake was significantly higher in the noise-forced groups than in the control group for one and two weeks, but did not change among the three groups for three weeks. The Ca content of the femur in the N-NE group was significantly decreased for one week, but was increased after two weeks, compared with the control group. Exercise controlled the reduction of the femur Ca content after one week of noise exposure, and caused an increase after two weeks, compared with the control group. Significant increases in the TBA value in both serum and liver were observed under noise exposure, and were mostly depressed by exercise.
