Jowsey J
J Clin Invest. 1972 Jan;51(1):9-15. doi: 10.1172/JCI106802.
The experiment was carried out on 3-month old puppies. Control animals received a diet normal in calcium and vitamin D. The diet for one group of experimental animals was deficient in both calcium and vitamin D, while another experimental group was fed a diet deficient in calcium but with adequate vitamin D. The response of these animals to injected parathyroid extract was evaluated over a 4 month period. The serum calcium response fell after approximately 20 days in both the calcium-deficient (vitamin D-replete) and the calcium- and vitamin D-deficient animals. The effect on the parathyroid response of the addition of calcium or vitamin D in vitamin D- and calcium-deficient animals was also evaluated. The addition of vitamin D to rachitic animals did not restore the response to parathyroid extract; however, in calcium- and vitamin D-deficient animals with normal calcium levels there was a restored response to parathyroid extract. Morphologic studies were made of the bone at various times during the experimental period; the presence of osteoid tissue correlated with the absence of a response to injected parathyroid extract. The results suggest that parathyroid hormone acts independently and requires the presence of mineralized bone for its action in raising the serum calcium. Vitamin D appears to be important in the mineralization of new bone tissue.
实验在3个月大的幼犬身上进行。对照动物给予钙和维生素D含量正常的饮食。一组实验动物的饮食中钙和维生素D都缺乏，而另一组实验组则喂食钙缺乏但维生素D充足的饮食。在4个月的时间里评估这些动物对注射甲状旁腺提取物的反应。在钙缺乏（维生素D充足）和钙及维生素D都缺乏的动物中，血清钙反应在大约20天后下降。还评估了在维生素D和钙缺乏的动物中添加钙或维生素D对甲状旁腺反应的影响。给佝偻病动物添加维生素D并不能恢复对甲状旁腺提取物的反应；然而，在钙和维生素D缺乏但钙水平正常的动物中，对甲状旁腺提取物的反应得到了恢复。在实验期间的不同时间对骨骼进行了形态学研究；类骨质组织的存在与对注射甲状旁腺提取物无反应相关。结果表明，甲状旁腺激素独立起作用，并且在提高血清钙的作用中需要矿化骨的存在。维生素D似乎在新骨组织的矿化中很重要。
