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.

Effect of Small Increments in Plasma Calcium Concentration on the Responsiveness of Forearm Resistance Vessels to Verapamil in Normal Subjects

1984 ◽  
Vol 67 (6) ◽  
pp. 613-618 ◽  
Author(s):  
B. F. Robinson ◽  
R. J. W. Phillips
Keyword(s):  
Calcium Concentration ◽  
Venous Blood ◽  
Normal Subjects ◽  
Plasma Calcium ◽  
Calcium Handling ◽  
Membrane Function ◽  
Resistance Vessels ◽  
Initial Control ◽  
Plasma Calcium Concentration ◽  
Small Increments

1. The effect of a small increase in local plasma calcium concentration on the responsiveness of the forearm resistance vessels to verapamil has been examined in normal subjects, by using a plethysmographic method with infusion of calcium and other agents into the brachial artery. 2. Infusion of calcium at a rate which increased the concentration in forearm venous blood by about 0.5 mmol/l caused basal blood flow to fall by 19% and the dilator response to verapamil to fall by 35% (n = 8; P<0.02). 3. When, after 46 min, the infusion of calcium was discontinued, the dilator response to verapamil increased to reach a level 53% higher than the initial control (n = 8; P<0.02). 4. Infusion of calcium had no effect on the dilator response to sodium nitroprusside. 5. Infusion of noradrenaline at a rate which caused a greater reduction in basal flow than that induced by calcium had no effect on the response to verapamil. 6. It is concluded that the dilator response to verapamil, which is thought to reflect activity of the potential operated system for calcium entry, is selectively depressed by a small elevation of plasma calcium concentration, but subsequently becomes elevated. These findings point to an important role for calcium in the regulation of membrane function in the resistance vessels and support the view that altered calcium handling may contribute to the development of primary hypertension.

PARATHYROID HORMONE IN FOETAL AND ADULT SHEEP: THE EFFECT OF HYPOCALCAEMIA

1972 ◽  
Vol 53 (3) ◽  
pp. 339-348 ◽  
Author(s):  
F. G. SMITH ◽  
D. PAULINE ALEXANDER ◽  
R. M. BUCKLE ◽  
H. G. BRITTON ◽  
D. A. NIXON
Keyword(s):  
Parathyroid Hormone ◽  
Calcium Concentration ◽  
Early Stage ◽  
Inverse Correlation ◽  
Maternal Plasma ◽  
Plasma Calcium ◽  
Foetal Life ◽  
Plasma Calcium Concentration ◽  
Range Of Values ◽  
Edta Infusion

SUMMARY Measurable levels of immunoassayable parathyroid hormone (PTH) were present in the plasma of two out of five sheep foetuses of 80–142 days gestational age, and in three of the mothers at Caesarian section. There was no correlation between foetal and maternal concentrations although the range of values was similar. In response to foetal hypocalcaemia induced by EDTA infusion the plasma PTH concentration rose in all of the foetuses and there was a highly significant inverse correlation between the foetal plasma calcium and PTH levels. During the period of foetal hypocalcaemia the maternal plasma PTH levels did not change significantly. EDTA was also infused into three adult ewes. There was a similar rise in the concentration of PTH in the plasma of these ewes and it was concluded that the level of responsiveness of the foetal parathyroid gland to plasma calcium concentration was similar to that of the adult. The parathyroid glands would appear to be active from an early stage in foetal life and responsive to changes in serum calcium level.

Plasma Magnesium and Calcium Levels in Depressive Psychosis

1972 ◽  
Vol 120 (559) ◽  
pp. 683-684 ◽  
Author(s):  
G. J. Naylor ◽  
Laura W. Fleming ◽  
W. K. Stewart ◽  
H. B. McNamee ◽  
D. Le Poidevin
Keyword(s):  
Divalent Cation ◽  
Calcium Concentration ◽  
Depressive Illness ◽  
Plasma Calcium ◽  
Ionized Calcium ◽  
Total Plasma ◽  
Total Calcium ◽  
Before And After ◽  
Plasma Calcium Concentration ◽  
Plasma Magnesium

There have been reports of the association of alterations in the divalent cation content of plasma with depressive illness. Coirault and colleagues (1959) found increased ionized calcium levels despite decreased total plasma calcium concentration in patients recovered from depression. More recently, Frizel and colleagues (1969) have reported normal plasma ionized and total calcium levels both before and after recovery from depression.

Evidence for a novel parathyroid hormone-related protein in fetal lamb parathyroid glands and sheep placenta: comparisons with a similar protein implicated in humoral hypercalcaemia of malignancy

1988 ◽  
Vol 117 (2) ◽  
pp. 261-271 ◽  
Author(s):  
C. P. Rodda ◽  
M. Kubota ◽  
J. A. Heath ◽  
P. R. Ebeling ◽  
J. M. Moseley ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Calcium Concentration ◽  
Plasma Calcium ◽  
Parathyroid Glands ◽  
Human Lung Cancer ◽  
Related Protein ◽  
Parathyroid Hormone Related Protein ◽  
Fetal Lamb ◽  
Plasma Calcium Concentration ◽  
Placental Extract

ABSTRACT Parathyroid hormone (PTH)-like bioactivity, assayed as adenylate cyclase response in UMR 106-01 osteogenic sarcoma cells, was present in extracts of sheep fetal and maternal parathyroid glands and placenta. Preincubation of extracts with PTH(1–34) antiserum inhibited approximately 40% of the bioactivity in fetal parathyroid extracts, 50% in maternal parathyroid extracts, but only 10% of the bioactivity in the placental extract. Partial purification of placental extracts by chromatography yielded fractions containing PTH-like bioactivity which were similar in behaviour to that of PTH-related protein (PTHrP) from a human lung cancer cell line (BEN). An antiserum against synthetic PTHrP(1–16) partially inhibited the bioactivity of the placental extract and synthetic PTHrP(1–34), but had no effect on the bioactivity of bovine PTH(1–34) or bovine PTH(1– 84). The placental PTH-like bioactivity was higher in mid- than in late gestation. Fetal parathyroid glands contained the highest PTH-like bioactivity. Thyroparathyroidectomy of one fetal twin lamb in each of 16 ewes between 110 and 125 days of gestation resulted in decreases of the plasma calcium concentration and reversal of the placental calcium gradient that existed between the ewe and the intact fetus. Perfusion of the placenta of each twin in anaesthetized ewes was carried out sequentially with autologous fetal blood in the absence of the exsanguinated fetus. The plasma calcium concentration in the blood perfusing the placenta of each twin increased, but reached a plateau at a lower concentration in the perfusing blood of thyroparathyroidectomized fetuses than in that of the intact fetuses. Addition of extracts of fetal parathyroid glands or of partially purified PTHrP resulted in further increases in plasma calcium in the autologous blood perfusing the placentae of thyroparathyroidectomized fetuses, but addition of bovine PTH(1–84) or rat PTH(1–34) had no effect. The presence of this PTH-like protein in the fetal parathyroid gland and placenta may contribute to the relative hypercalcaemia of the fetal lamb. This protein, which is similar to PTHrP associated with humoral hypercalcaemia of malignancy, stimulates the placental calcium pump responsible for maintaining a relative fetal hypercalcaemia during gestation. J. Endocr. (1988) 117, 261–271

Effect of differing concentrations of parathyroid hormone on rat renal electrolyte excretion

1982 ◽  
Vol 243 (5) ◽  
pp. F514-F517
Author(s):  
S. Carney ◽  
L. Thompson
Keyword(s):  
Parathyroid Hormone ◽  
Calcium Concentration ◽  
Fold Increase ◽  
Urinary Calcium ◽  
Plasma Calcium ◽  
Calcium Excretion ◽  
Physiological Concentration ◽  
Phosphate Excretion ◽  
Plasma Calcium Concentration ◽  
Magnesium Excretion

Urinary clearance studies were performed on acutely thyroparathyroidectomized rats to study the effect of a range of parathyroid hormone (PTH) concentrations on renal electrolyte transport. PTH 0.1 U, prime and per hour, significantly increased the plasma calcium concentration, yet fractional calcium excretion was increased by 47.5% and inorganic phosphate excretion remained unaltered. PTH 1 U produced a similar increase in the plasma calcium concentration. However, urinary calcium excretion was unchanged when compared with control animals and a small phosphaturia occurred (from 0.1 +/- 0.1 to 0.8 +/- 0.2%; P less than 0.05). PTH 10 U decreased fractional calcium excretion by 50% and increased fractional phosphate excretion from 0.4 +/- 02. to 19.4 +/- 1.7% (P less than 0.01). Changes in urinary magnesium excretion were similar to those of calcium, being increased with the lowest PTH concentration yet decreased with a 100-fold increase in PTH concentration. These data suggest that PTH, at a low physiological concentration that acts on bone, does not directly alter renal electrolyte handling. High physiological concentrations of PTH, however, produce a brisk phosphaturia and reduce calcium and magnesium excretion. A reappraisal of the accepted role of PTH on renal calcium conservation is therefore required.

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