Author/Editor     Benedik, M
Title     Kalcijeva in fosforna paradigma
Type     članek
Source     In: Buturović-Ponikvar J, Bren AF, editors. Zbornik 2. slovenski nefrološki kongres z mednarodno udeležbo ob 30. letnici dialize in transplantacije ledvic v Sloveniji; 2000 sep 27-30; Brdo pri Kranju. Ljubljana: Klinični center, Klinični oddelek za nefrologijo,
Publication year     2000
Volume     str. 147-53
Language     slo
Abstract     The concentrations of calcium and phosphorus are tightly regulated in patients with chronic renal failure. In patients with normal renal failure serum concentrations of calcium and phosphate are maintained through the interaction of parathyroid hormone and calcitriol. Parathyroid hormone acts directly on bone and kidney and indirectly on the intestine. The amount of excreted phosphorus through the kidney is determined through the balance of ultrafiltration and reabsorption, where play important roles the concentrations of parathyroid hormone and calcitriol. In chronic renal failure the excretion of phosphate through the kidney is not adequate and phosphate retention in the body occurs. Because of phosphate retention is decreased production of calcitriol in renal tubules, so that the homeostatic system of calcium, phosphate and calcitriol is disturbed. Because of lower production of calcitriol in the kidney, intestinal calcium absorption is reduced and the concentration of ionized calcium is lowered. In the mechanism of vitamin D effects vitamin D receptor has very important place. The calcium-ion-sensing receptor is a key component of the mechanism that establishes the set point of the parathyroids and the level of calcium ions in extracellular fluid. The abnormality in the ability to sense calcium-ion concentrations could be the result of abnormality of this receptor in secondary hyperparathyriodism. Because of all these factors the secretion of parathyroid hormone from the parathyroids is higher, and parathyroid hyperplasia and secondary hyperparathyriodism occur. An additional mechanism contributing to reduced calcium serum level is the precipitation of calcium phosphate in soft tissues and into the skin (metastatic calcifications).The key metastatic factor is high CaX P product. (Abstract truncated at 2000 characters.)
Descriptors     CALCIUM METABOLISM DISORDERS
PHOSPHORUS METABOLISM DISORDERS
KIDNEY FAILURE, CHRONIC