Vasoactive intestinal polypeptide stimulates parathyroid hormone release by interaction with cyclic adenosine monophosphate production of bovine parathyroid cells

1991 ◽  
Vol 124 (1) ◽  
pp. 54-59 ◽  
Author(s):  
Henrik Joborn ◽  
Rolf Larsson ◽  
Jonas Rastad ◽  
Peter Nygren ◽  
Göran Åkerström ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Vasoactive Intestinal Polypeptide ◽  
Adenosine Monophosphate ◽  
Extracellular Calcium ◽  
Dependent Manner ◽  
Hormone Release ◽  
Physiological Concentration ◽  
Adult Cattle ◽  
Parathyroid Hormone Release ◽  
Intestinal Polypeptide

Abstract. Influence of vasoactive intestinal polypeptide, neuropeptide Y, calcitonin gene-related peptide, and substance P was investigated on dispersed parathyroid cells of adult cattle. At a physiological concentration of extracellular calcium, vasoactive intestinal polypeptide stimulated the parathyroid hormone release in a dose-dependent manner, whereas no effects were noted for the other peptides. The dependency of PTH secretion upon extracellular calcium was shifted to the right by vasoactive intestinal polypeptide at 10−6 mol/l, with a tendency for greater effects at low (0.5 mmol/l) than high concentrations (2.0-3.0 mmol/l) of the cation. Vasoactive intestinal polypeptide significantly enhanced cAMP release of the parathyroid cells, whereas no influence was noted on cytoplasmic calcium or pH within the cells. The results suggest that vasoactive intestinal polypeptide stimulates the PTH release by interaction with cAMP production of the parathyroid cells. This effect may contribute to the development of hypercalcemia in patients with neuroendocrine tumours secreting vasoactive intestinal polypeptide.

Relationship between external and cytoplasmic calcium concentrations, parathyroid hormone release and weight of parathyroid glands in human hyperparathyroidism

1988 ◽  
Vol 116 (3) ◽  
pp. 457-464 ◽  
Author(s):  
C. Wallfelt ◽  
E. Gylfe ◽  
R. Larsson ◽  
S. Ljunghall ◽  
J. Rastad ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Calcium Concentration ◽  
Hormone Release ◽  
Cytoplasmic Calcium ◽  
Serum Concentrations ◽  
Maximal Inhibition ◽  
Adult Cattle ◽  
Calcium Effects ◽  
The Individual ◽  
Parathyroid Hormone Release

ABSTRACT Parathyroid hormone (PTH) release and cytoplasmic calcium concentrations were investigated at ambient calcium concentrations of 0·5–3·0 mmol/l in dispersed parathyroid cells from 44 hypercalcaemic patients with primary or uraemic hyperparathyroidism (HPT). In comparison with parathyroid cells from adult cattle, release of PTH by human preparations was reduced and values of the ambient calcium concentration causing half-maximal inhibition of PTH release (median effective dose, ED50) were significantly increased. Half-maximal inhibition of PTH release was obtained with concentrations of cytoplasmic calcium almost identical to the concentrations of ionized calcium in the plasma of the individual patients. Cytoplasmic concentrations of calcium in the parathyroid cells were inversely related to release of PTH. Concentrations of cytoplasmic calcium were significantly lower in human than in bovine cells and the ED50 for ambient calcium increase on cytoplasmic calcium was raised to the same extent as the ED50 for ambient calcium inhibition of PTH release in human compared with bovine cells. The magnitude of the increased ED50 for ambient calcium inhibition of PTH release and increase of cytoplasmic calcium concentration was similar in adenomas and sporadic as well as hereditary primary hyperplasias, but the secretion was the least aberrant in uraemic hyperplasias, although they had by far the largest glandular mass. Serum concentrations of total calcium before surgery correlated with the ED50 for ambient calcium effects of PTH release and cytoplasmic calcium, but not with glandular weight. These findings demonstrate a universally abnormal regulation of cytoplasmic calcium in HPT and its importance for PTH release, and that disturbance of cytoplasmic calcium rather than the increased glandular mass contributes to the hypercalcaemia in adenomatous and hyperplastic HPT. J. Endocr. (1988) 116, 457–464

Potassium stimulates parathyroid hormone release in the absence of extracellular calcium

1983 ◽  
Vol 32 (1) ◽  
pp. 1-12 ◽  
Author(s):  
P. Olles ◽  
F. Tschopp ◽  
D.W. Dempster ◽  
P.H. Tobler ◽  
R. Muff ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Extracellular Calcium ◽  
Hormone Release ◽  
Parathyroid Hormone Release
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