The effect of weight-bearing on the bone tissue of bipedal rats

Abstract

In order to study the effect of weight-bearing on the maintenance and increase of bone mass, bipedal rats were prepared and changes in the lumbar vertebrae and hindlimb bones were observed. The bone area of the lumbar vertebrae was elavated in bipedal rats, possibly in response to the increase in weight-bearing by the lumbar vertebrae. The response observed in bipedal rats with osteoporosis was dependent on their calcium (Ca) intake. The bone area of the lumbar vertebrae, which failed to increase on a low-Ca diet, did increase when the rats were placed on a high-Ca diet. Weight-bearing was beneficial in increasing bone mass and was also effective in counteracting the decrease in bone mass in osteoporosis; however, an adequate supply of Ca appears to be necessary. © 1994 Japanese Society of Bone Metabolism Research.