Is control of secondary hyperparathyroidism optimal with the currently used calcium concentration in the CAPD fluid?

1992 ◽  
Vol 6 (3) ◽  
pp. 310-310
Author(s):  
T. Weinreich ◽  
M. Rambausek ◽  
E. Ritz
Keyword(s):  
Secondary Hyperparathyroidism ◽  
Calcium Concentration

scholarly journals High phosphate level directly stimulates parathyroid hormone secretion and synthesis by human parathyroid tissue in vitro.

1998 ◽  
Vol 9 (10) ◽  
pp. 1845-1852
Author(s):  
Y Almaden ◽  
A Hernandez ◽  
V Torregrosa ◽  
A Canalejo ◽  
L Sabate ◽  
...  
Keyword(s):  
Secondary Hyperparathyroidism ◽  
Calcium Concentration ◽  
Statistical Significance ◽  
Hormone Secretion ◽  
Parathyroid Tissue ◽  
Parathyroid Glands ◽  
Mrna Levels ◽  
High Calcium ◽  
High Phosphate

Phosphate retention plays an important role in the pathogenesis of secondary hyperparathyroidism in patients with renal failure. In in vitro studies, high extracellular phosphate levels directly stimulate PTH secretion in rat and bovine parathyroid tissue. The present study evaluates the effect of high phosphate levels on the secretion of PTH and the production of prepro PTH mRNA in human hyperplastic parathyroid glands. The study includes parathyroid glands obtained from patients with primary adenomas and from hemodialysis and kidney-transplant patients with diffuse and nodular secondary hyperplasia. The experiments were performed in vitro using small pieces of parathyroid tissue. The ability of high calcium levels to decrease PTH secretion was less in adenomas than in secondary hyperplasia; among the secondary hyperplasia, nodular was less responsive to an increase in calcium than diffuse hyperplasia. In diffuse hyperplasia, PTH secretion was increased in response to 3 and 4 mM phosphate compared with 2 mM phosphate, despite a high calcium concentration in the medium; prepro PTH mRNA levels increased after incubation in 4 mM phosphate. Similar results were obtained with nodular hyperplasia, except that the elevation of PTH secretion in response to 3 mM phosphate did not attain statistical significance. In adenomas, high calcium concentrations (1.5 mM) did not result in inhibition of PTH secretion, independent of the phosphate concentration, and the prepro PTH mRNA was not significantly increased by high phosphate levels. In conclusion, first, the PTH secretory response to an increase in calcium concentration is less in nodular than diffuse hyperplasia; second, high phosphate levels directly affect PTH secretion and gene expression in patients with advanced secondary hyperparathyroidism.

Parathyroid Hormone-like Biological Activity in Urine

1978 ◽  
Vol 54 (4) ◽  
pp. 349-353 ◽  
Author(s):  
N. Nijs-De Wolf ◽  
N. De Nutte ◽  
H. Brauman ◽  
J. Corvilain
Keyword(s):  
Biological Activity ◽  
Parathyroid Hormone ◽  
Secondary Hyperparathyroidism ◽  
Calcium Concentration ◽  
Normal Volunteer ◽  
Normal Subjects ◽  
Plasma Calcium ◽  
Surgical Removal ◽  
Before And After ◽  
Plasma Calcium Concentration

1. The parathyroid hormone-like biological activity of concentrated urine was measured by the increase of plasma calcium concentration after intravenous injection of the sample into chickens. 2. Urine was tested in hypoparathyroid patients, normal volunteer subjects, primary hyperparathyroid patients before and after surgery and patients with secondary hyperparathyroidism. 3. In primary and secondary hyperparathyroidism the biological activity was significantly higher than in urine from normal subjects, which was in turn significantly higher than the activity in the urine of hypoparathyroid patients. This bioactivity diminished after surgical removal of a hyperparathyroid adenoma. 4. Decreased activity after trypsinization indicated the peptidic nature of the hypercalcaemic substance.

scholarly journals Low-calcium dialysate stimulates parathormone secretion and its long-term use worsens secondary hyperparathyroidism.

1995 ◽  
Vol 6 (1) ◽  
pp. 132-135
Author(s):  
E Fernández ◽  
M Borràs ◽  
B Pais ◽  
J Montoliu
Keyword(s):  
Secondary Hyperparathyroidism ◽  
Serum Calcium ◽  
Calcium Concentration ◽  
Hemodialysis Patients ◽  
Clinical Effects ◽  
Calcium Balance ◽  
Serum Ipth ◽  
Low Calcium ◽  
High Calcium

The long-term clinical effects of the use of a low calcium concentration in the dialysate are largely unknown. For this reason, the influence of low-calcium dialysate on parathyroid hormone (PTH) secretion in hemodialysis patients and its long-term effect on the severity of secondary hyperparathyroidism were studied. In 35 hemodialysis patients, the dialysate calcium concentration was lowered from 1.75 to 1.25 mmol/L. Twelve months later, serum iPTH levels increased significantly from 18.6 to 33.2 pmol/L and so did alkaline phosphatase levels, from 210 to 330 IU/L, without significant changes in serum calcium or phosphorus levels. Hemodialysis with low-calcium dialysate (1.25 mmol/L) induced a net calcium loss in 10 patients, without modifications in ionized serum calcium levels. In addition, mean serum iPTH increased 20% over baseline levels, reaching the maximal level at 30 min after the start of hemodialysis with low-calcium dialysate. In contrast, mean serum iPTH levels drop dramatically at 30 min of hemodialysis with high-calcium dialysate (1.75 mmol/L). It was concluded that low-calcium dialysate worsens secondary hyperparathyroidism in hemodialysis patients, probably by inducing a negative calcium balance and causing repetitive stimulation of PTH secretion in each dialysis. The maintenance of normal serum calcium levels could be due to PTH-induced calcium mobilization from bone.

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