Physiological basis for absorptive and renal hypercalciurias.
Physiological basis for absorptive and renal hypercalciurias.
复制标题
吸收性和肾性高钙尿症的生理基础。
作者：
C. Pak
特发性高钙尿症包括两种主要类型：吸收性高钙尿症，以原发性肠钙吸收过多为特征;肾性高钙尿症，以肾小管钙重吸收受损为主要特征。这两种形式的高钙尿症可以相互区分，因为a）甲状旁腺功能在肾性高钙尿症中受到刺激，但在吸收性高钙尿症中正常或受到抑制，B）肾性高钙尿症中存在钙的肾漏，但在吸收性高钙尿症中不存在，c）肠钙吸收可能主要在吸收性高钙尿症中增加，其次是肾性高钙尿症（由甲状旁腺激素过量引起），d）肾性高钙尿症中钙吸收增加可能由甲状旁腺依赖性刺激1，25-二羟维生素D合成引起，而在吸收性高钙尿症中可能是维生素D非依赖性的，e）这两种病症对某些治疗的反应是独特的，和f）甲状旁腺激素过量的后遗症，例如低骨密度和负钙平衡，可能存在于肾性高钙尿症中，而在吸收性高钙尿症中则没有。这些发现提供了一个生理基础的考虑吸收性和肾高钙尿症作为不同的和独立的实体。
Idiopathic hypercalciuria constitutes two major variants-absorptive hypercalciuria, characterized by a primary intestinal hyperabsorption of calcium, and renal hypercalciuria, in which renal tubular reabsorption of calcium is primarily impaired. The two forms of hypercalciuria may be distinguished from each other, since a) parathyroid function is stimualted in renal hypercalciuria, but normal or suppressed in absorptive hypercalciuria, b) the renal leak of calcium is present in renal hypercalciuria, but not in absorptive hypercalciuria, c) intestinal calcium absorption is probably increased primarily in absorptive hypercalciuria, and secondarily in renal hypercalciuria (from parathyroid hormone excess), d) the increased calcium absorption in renal hypercalciuria probably results from the parathyroid hormone-dependent stimulation of 1,25-dihydroxyvitamin D synthesis, whereas that in absorptive hypercalciuria may be vitamin D-independent, e) the response of the two conditions to certain treatments is unique, and f) the sequelae of parathyroid hormone excess, such as low bone density and negative calcium balance, may be present in renal hypercalciuria, but not in absorptive hypercalciuria. These findings provide a physiological basis for the consideration of absorptive and renal hypercalciurias as distinct and separate entities.