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.

scholarly journals Hysteresis of the parathyroid hormone response to hypocalcemia in hemodialysis patients with low turnover aluminum bone disease.

1991 ◽  
Vol 2 (6) ◽  
pp. 1136-1143
Author(s):  
A J Felsenfeld ◽  
D Ross ◽  
M Rodriguez
Keyword(s):  
Parathyroid Hormone ◽  
Serum Calcium ◽  
Bone Disease ◽  
Calcium Concentration ◽  
Hemodialysis Patients ◽  
Ionized Calcium ◽  
Total Serum ◽  
High Calcium ◽  
The Mean ◽  
Pth Level

During the study of parathyroid function in 19 hemodialysis patients with low turnover aluminum bone disease, it was observed that serum parathyroid hormone (PTH) levels were higher during the induction of hypocalcemia than during the recovery from hypocalcemia. This type of PTH response has been termed hysteresis. Hypocalcemia was induced during hemodialysis with a calcium-free dialysate. When the total serum calcium level decreased to 7 mg/dL, the dialysate calcium concentration was changed to 3.5 mEq/L and the dialysis session was completed. One week later, hypercalcemia was induced during hemodialysis with a high-calcium dialysate. The mean basal PTH level was 132 +/- 37 pg/mL (normal, 10 to 65 pg/mL; immunoradiometric (IRMA), Nichols Institute, San Juan Capistrano, CA) and increased to a maximal PTH level of 387 +/- 91 pg/mL during hypocalcemia. For the same ionized calcium concentration, the PTH level was higher during the induction of hypocalcemia than during the recovery from hypocalcemia. Conversely, for the same ionized calcium concentration, the PTH level was greater when hypercalcemia was induced from the nadir of hypocalcemia than when hypercalcemia was induced from basal serum calcium. The set point of calcium (defined as the serum calcium concentration required to reduce maximal PTH by 50%) was greater during the induction of hypocalcemia than during the recovery from hypocalcemia (4.44 +/- 0.10 versus 4.25 +/- 0.09 mg/dL; P = 0.03). The mean basal ionized calcium concentration and the mean ionized calcium concentration at the intersection of the two PTH-calcium curves were the same (4.61 +/- 0.13 versus 4.61 +/- 0.12 mg/dL).(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals The beneficial effect of the sap of Acer mono in an animal with low-calcium diet-induced osteoporosis-like symptoms

2008 ◽  
Vol 100 (5) ◽  
pp. 1011-1018 ◽  
Author(s):  
Geun-Shik Lee ◽  
Hyuk-Soo Byun ◽  
Man-Hee Kim ◽  
Bo-Mi Lee ◽  
Sang-Hwan Ko ◽  
...  
Keyword(s):  
Serum Calcium ◽  
Calcium Concentration ◽  
Negative Control ◽  
Spring Water ◽  
Calcium Diet ◽  
Low Calcium Diet ◽  
Low Calcium ◽  
High Calcium ◽  
Femur Density ◽  
Acer Mono

The sap of Acer mono has been called ‘bone-benefit-water’ in Korea because of its mineral and sugar content. In particular, the calcium concentration of the sap of A. mono is 37·5 times higher than commercial spring water. In the current study, we examined whether A. mono sap could improve or prevent osteoporosis-like symptoms in a mouse model. Male mice (3 weeks old) were fed a low-calcium diet supplemented with 25, 50 or 100 % A. mono sap, commercial spring water or a high calcium-containing solution as a beverage for 7 weeks. There were no differences in weekly weight gain and food intake among all the groups. Mice that were given a low-calcium diet supplemented with commercial spring water developed osteoporosis-like symptoms. To assess the effect of sap on osteoporosis-like symptoms, we examined serum calcium concentration, and femur density and length, and carried out a histological examination. Serum calcium levels were significantly lower in mice that received a low-calcium diet supplemented with commercial spring water (the negative control group), and in the 25 % sap group compared to mice fed a normal diet, but were normal in the 50 and 100 % sap and high-calcium solution groups. Femur density and length were significantly reduced in the negative control and 25 % sap groups. These results indicate that a 50 % sap solution can mitigate osteoporosis-like symptoms induced by a low-calcium diet. We also examined the regulation of expression of calcium-processing genes in the duodenum and kidney. Duodenal TRPV6 and renal calbindin-D9k were up-regulated dose-dependently by sap, and the levels of these factors were higher than those attained in the spring water-treated control. The results demonstrate that the sap of A. mono ameliorates the low bone density induced by a low-calcium diet, most likely by increasing calcium ion absorption.

scholarly journals Secretion and degradation of parathormone as a function of intracellular maturation of hormone pools

1979 ◽  
Vol 83 (3) ◽  
pp. 521-528 ◽  
Author(s):  
JJ Morrissey ◽  
DV Cohn
Keyword(s):  
Cyclic Amp ◽  
Half Life ◽  
Calcium Concentration ◽  
Hormone Secretion ◽  
Ionized Calcium ◽  
Dibutyryl Cyclic Amp ◽  
Low Calcium ◽  
High Calcium ◽  
Parathormone Secretion

The biosynthesis, processing, and secretion of parthormone and the effect of calcium on these processes were measured in dispersed porcine parthyroid cells incubated with [(35)S]methionine. Proparathormone was detected at 10 min, the earliest time measured, and was rapidly and apparently quantitatively converted to parathormone. The half-life of the prohomormone pool was 15 min. Secretion of parathormone was detected by 20 min. In pulse-chase experiments there was a period between 20 and 40 min during which the wave of newly-synthesized parathormone was secreted. After 40 min during little additional radioactive hormone was secreted, but dibutyryl cyclic AMP, an agent that can mobilize stored parathormone, when added to the incubation mixtures enhanced radioactive parathormone secretion but only after 60 min, although it increased net hormone secretion as determined by radioimmunoassay to the same extent at all times studied. When the ionized calcium concentration of the medium was lowered, more radioactive hormone was secreted at all times but the effect was greatest on that hormone that was synthesized less than 60 min previously ; however, net hormone secretion in contrast to radioactive hormone was enhanced equally at all intervals. These data could mean that the refractoriness to secretion of parathormone 40-60 min of age was related to maturation of secretory container preparatory to storage. Low calcium (0.5 mM) stimulated hormone secretion up to fivefold compared to high calcium (3.0 mM) but did not affect synthesis of parathormone or proparathormne or conversion of the latter to hormone. During processing at least 70 percent of the intracellular parathormone was lost, presumably through proteolysis and this degradation was greater at high calcium. These data have been interpreted in light of the concept that two secretable pools of parathormone exist within the parathyroid.

scholarly journals Differences in the dynamics of parathyroid hormone secretion in hemodialysis patients with marked secondary hyperparathyroidism.

1995 ◽  
Vol 6 (5) ◽  
pp. 1371-1378
Author(s):  
A J Felsenfeld ◽  
A Jara ◽  
M Pahl ◽  
J Bover ◽  
M Rodriguez
Keyword(s):  
Parathyroid Hormone ◽  
Secondary Hyperparathyroidism ◽  
Serum Calcium ◽  
Hormone Secretion ◽  
Hemodialysis Patients ◽  
Basal Serum ◽  
Group I ◽  
The Difference ◽  
Pth Level ◽  
Uniform Group

Hemodialysis patients with predialysis intact parathyroid hormone (PTH) levels of more than 500 pg/mL are generally considered to have marked secondary hyperparathyroidism. Because the serum calcium level in these patients varies from low to high, it is not clear whether every hemodialysis patient with a PTH level > 500 pg/mL is part of a uniform group. The dynamics of PTH secretion in 21 hemodialysis patients with predialysis (basal) intact PTH levels > 500 pg/mL (range, 506 to 1978 pg/mL) has been evaluated. The basal/maximal PTH ratio, an indicator of the degree of relative PTH stimulation in the baseline state, was inversely correlated with the maximal PTH (r = -0.71), the basal serum calcium (r = -0.70), and the difference between the serum calcium at basal and maximal PTH (r = 0.81); the latter is the decrement in serum calcium from baseline necessary to maximally stimulate PTH. Because the basal PTH level appeared to be disproportionately influenced by hypocalcemia, the 21 patients were separated into two groups on the basis of the basal serum calcium (Group I < 9 mg/dL and Group II > 9 mg/dL). Basal PTH was not different between the two groups, even though maximally stimulated PTH (1,219 +/- 204 versus 2,739 +/- 412 pg/mL; P < 0.01) as induced by hypocalcemia and maximally suppressed PTH (217 +/- 37 versus 528 +/- 104; P = 0.05) as induced by hypercalcemia were less in Group I with the low basal calcium; moreover, the ratio of basal/maximal PTH was higher (73 +/- 6 versus 47 +/- 5%; P < 0.01) in Group I with the low basal calcium. These results suggest that the reason for a basal PTH > 500 pg/mL may be different among hemodialysis patients. In hypocalcemic patients, the low serum calcium appeared to be a major impetus for the high basal PTH level. In conclusion, (1) the maximally stimulated PTH appears to provide a better means of separating patients with marked secondary hyperparathyroidism than the basal PTH and (2) hemodialysis patients with basal PTH levels > 500 pg/mL may not be a uniform group.

scholarly journals Low serum calcium: a new, important indicator of COVID-19 patients from mild/moderate to severe/critical

2020 ◽  
Vol 40 (12) ◽  
Author(s):  
Xi Zhou ◽  
Dong Chen ◽  
Lan Wang ◽  
Yuanyuan Zhao ◽  
Lai Wei ◽  
...  
Keyword(s):  
Viral Infection ◽  
Serum Calcium ◽  
Symptom Onset ◽  
Calcium Level ◽  
Early Stage ◽  
Multiple Organ ◽  
Clinical Severity ◽  
Calcium Balance ◽  
Important Indicator ◽  
Low Calcium

Abstract Background: Coronavirus disease 2019 (COVID-19) virus is still spreading, finding out the initial hits of viral infection is important to minimize the mild/moderate population, prevent disease aggravation and organs dysfunction. Objective: We investigated COVID-19 patients with different serum calcium levels. Design: We checked the serum calcium level of the patients based on days after symptom onset as well as the severity of COVID-19. We also checked multiorgan injuries and immune cytokines level in their blood. Results: Both mild/moderate and severe critical cases we observed showed low calcium level in the early stage of viral infection, while the severe/critical cases showed significant lower calcium level than mild/moderate cases in the early stage. We also found that low calcium level related to severe/critical multiorgan injuries especially in the mild/moderate population. Proinflammatory cytokine IL-6 also correlated to calcium change in both mild/moderate and severe/critical cases. Conclusions: Our finding indicates that calcium balance is a primal hit of COVID-19 and a biomarker of clinical severity at the beginning of symptom onset. Calcium is closely associated with virus-associated multiple organ injuries and the increase in inflammatory cytokines. Our results provide a new, important indicator of COVID-19 patients from mild/moderate to severe/critical: serum calcium.

Ambient pH and Calcium Concentration as Modifiers of Growth and Calcium Dynamics of Brook Trout, Salvelinus fontinalis

1984 ◽  
Vol 41 (12) ◽  
pp. 1774-1780 ◽  
Author(s):  
David W. Rodgers
Keyword(s):  
Brook Trout ◽  
Calcium Concentration ◽  
Salvelinus Fontinalis ◽  
Axial Skeleton ◽  
Low Ph ◽  
Fish Growth ◽  
Calcium Dynamics ◽  
Experimental Fish ◽  
Low Calcium ◽  
High Calcium

Juvenile brook trout, Salvelinus fontinalis, were maintained in water of pH 5.3 or 6.5 and calcium concentrations of 5 or 40 mg/L to determine the effects of these factors on fish growth and calcium dynamics. Growth rates varied more than twofold and were significantly reduced by both low ambient calcium concentration and low pH. In contrast, calcium dynamics of the fish were significantly affected by calcium concentration but not pH. Brook trout in low-calcium water retained less labeled dietary calcium and deposited less labeled calcium in axial skeleton and visceral tissues than fish in high-calcium water. Calcium concentrations of the skin and fins were slightly but significantly reduced among fish in low-calcium water, but neither pH nor ambient calcium concentration significantly affected ash content or calcium concentration of axial skeleton and visceral tissues of experimental fish.

Long-term effects of etelcalcetide as intravenous calcimimetic therapy in hemodialysis patients with secondary hyperparathyroidism

2017 ◽  
Vol 22 (2) ◽  
pp. 426-436 ◽  
Author(s):  
Takashi Shigematsu ◽  
◽  
Masafumi Fukagawa ◽  
Keitaro Yokoyama ◽  
Takashi Akiba ◽  
...  
Keyword(s):  
Secondary Hyperparathyroidism ◽  
Hemodialysis Patients ◽  
Long Term Effects

scholarly journals NEWCASTLE DISEASE ANTIBODY TITRE IS DEPENDENT ON SERUM CALCIUM CONCENTRATION

2000 ◽  
Vol 48 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Jasminka Božičković ◽  
Gabrijela Krivec ◽  
W. L. Ragland ◽  
H. Mazija ◽  
P. Božičković ◽  
...  
Keyword(s):  
Serum Calcium ◽  
Newcastle Disease ◽  
Calcium Concentration ◽  
Dietary Calcium ◽  
Serum Calcium Concentration ◽  
Calcium Diet ◽  
Low Calcium Diet ◽  
High Calcium ◽  
Antibody Titres ◽  
Disease Antibody

Chickens were fed diets having optimal, high, and low levels of calcium for 42 days. Serum samples were collected at 14, 28 and 42 days of age, and serum calcium and haemagglutination inhibition titres for Newcastle disease virus were measured. The chickens were vaccinated at 14 days for Newcastle disease. Antibody titres were significantly increased by high dietary calcium and depressed by low dietary calcium. Mean titre was 2.5 (log2) for the optimal diet, 3.2 for the high-calcium diet, and 1.6 for the low-calcium diet. Antibody titres were dependent on serum calcium concentration (r2= 0.98 at 14 days, 0.99 at 28 days, and 0.78 at 42 days).

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