Effect of physical activity on calciotropic hormones and calcium balance in rats

1990 ◽  
Vol 258 (2) ◽  
pp. E263-E268 ◽  
Author(s):  
J. K. Yeh ◽  
J. F. Aloia
Keyword(s):  
Parathyroid Hormone ◽  
Bone Mass ◽  
Bone Turnover ◽  
Intestinal Absorption ◽  
Calcium Absorption ◽  
Serum Alkaline Phosphatase ◽  
Control Group ◽  
Calcium Balance ◽  
Calciotropic Hormones ◽  
Nephrogenous Camp

The response of calciotropic hormones and bone turnover to exercise and immobilization was examined by the measurement of calcium balance, bone turnover indexes, levels of parathyroid hormone, nephrogenous adenosine 3',5'-cyclic monophosphate (cAMP), and 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] weekly for 6 wk in three groups of rats: control, exercise trained, and immobilized. Early in the experiment, increases were observed in excretion of urinary calcium, hydroxyproline, and in serum alkaline phosphatase after both exercise and immobilization. It was not until the latter part of the experimental period that changes were observed in nephrogenous cAMP and intestinal absorption efficiency of calcium. In the fasting state, the exercise group had a drop in serum calcium and phosphate and a rise in nephrogenous cAMP and serum 1,25(OH)2D3 compared with the control group. The exercised animals experienced an increase in bone mass, whereas the immobilized animals had a decline in bone mass. Thus exercise stimulates bone growth, resulting in an increased demand for minerals that is satisfied by an increase in serum 1,25(OH)2D3 levels and increased intestinal absorption of calcium. The increase in calcium absorption suppresses parathyroid hormone production (nephrogenous cAMP) in the exercised animal. Immobilization resulted in increased bone resorption that suppressed parathyroid hormone, nephrogenous cAMP, and the intestinal absorption of calcium.

scholarly journals Central Neural Regulation of Parathyroid Hormone

2020 ◽  
Author(s):  
L. Zhang ◽  
N. Liu ◽  
J. Shao ◽  
D. Gao ◽  
Y. Liu ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Bone Mass ◽  
Bone Turnover ◽  
Paraventricular Nucleus ◽  
Calcium Homeostasis ◽  
Neural Regulation ◽  
Brain Nuclei ◽  
Trabecular Bone Mass ◽  
Serum Pth ◽  
Stimulation Of

AbstractParathyroid hormone (PTH) is one of the most important hormones responsible for bone turnover and calcium homeostasis, however, the mechanism underlying central neural regulation of PTH in mammals remains largely unknown. In this study, we identified the subfornical organ (SFO) and the paraventricular nucleus (PVN) as two important brain nuclei responded to serum PTH and calcium changes. Using chemogenetics, we found that serum PTH was suppressed by stimulation of SFOGABA neurons followed by a decrease in trabecular bone mass. Conversely, stimulation of SFOVGlut neurons promoted serum PTH and bone mass. The paraventricular nucleus (PVN) is downstream of the SFO, and chemogenetic activation of PVNCaMKII and PVNVGlut neurons induced an increase in serum PTH. These findings reveal important central neural nodes and will advance our understanding of the central neural regulation of PTH at the molecular, cellular and circuit level.

The Role of Parathyroid Hormone in the Gastro-Intestinal Absorption of Calcium

1970 ◽  
Vol 39 (1) ◽  
pp. 89-94 ◽  
Author(s):  
M. R. Wills ◽  
J. Wortsman ◽  
C. Y. C. Pak ◽  
F. C. Bartter
Keyword(s):  
Parathyroid Hormone ◽  
Intestinal Absorption ◽  
Calcium Absorption ◽  
Control Period ◽  
Normal Subjects ◽  
Parathyroid Extract

1. Gastrointestinal calcium absorption was studied in six normal subjects and in one patient with idiopathic hypoparathyroidism during a control period and during treatment with parathyroid extract. 2. In all subjects there was a small increase in the gastro-intestinal absorption of calcium during the administration of parathyroid extract.

scholarly journals Diagnosed Changes of Bone Mineral Density and Level of Calciotropic Hormones in Juvenile Hyperthyroidism

2021 ◽  
Author(s):  
Shakhlo Muratova
Keyword(s):  
Bone Mineral Density ◽  
Vitamin D ◽  
Bone Mass ◽  
Children And Adolescents ◽  
Bone Mineral ◽  
Control Group ◽  
Childhood And Adolescence ◽  
Healthy Children ◽  
Mineral Density ◽  
Calciotropic Hormones

Abstract In childhood and adolescence, a genetically determined bone mass accumulates, which ensures the strength of the skeleton throughout life. But with thyrotoxicosis, a separation of the processes of bone resorption and synthesis and the formation of sites of osteoporosis and osteosclerosis occur, leading to the loss of 10% of bone mass in 1 cycle of remodeling. Because of the lack of information about this phenomenon, our work aimed to study the state of bone mineral density and levels of calciotropic hormones in children and adolescents with thyrotoxicosis. The study was conducted by 19 children and adolescents with thyrotoxicosis. The control group consisted of 23 healthy children and adolescents. All studies were conducted in the RSSPMCE. Thyroid status, PTH and vitamin D were determined using a closed-type immunochemistry analyser Cobas e 411 Hitachi company HoffmanLeRoche (Switzerland) and its reagents. Bone mineral density was evaluated by dual-energy absorptiometry on a Stratos X-ray densitometer from DMS, France. The results of the study showed that the average value of the level of vitamin D in the group with thyrotoxicosis was 12.3 ± 1.1 ng/ml, against 20.4 ± 6.2 ng/ml of the control group, while its deficiency was diagnosed in 84.2%, and its insufficiency - in 15.8% of pediatric patients. In the group with thyrotoxicosis, the average level of PTH was lower and amounted to 45.1 ± 23.9 ng/ml (p < 0.05) compared with the control (49.2 ± 21.3 ng/ml); hypoparathyroidism was found in 4.9 times more often than among healthy children, and 21.1% showed an increase in the level of PTH. In children and adolescents with thyrotoxicosis Z- index of the femoral neck, lumbar vertebrae and the general body were significantly lower than in the control group. 36.8% of children with thyrotoxicosis have osteoporosis. Conclusion: Thyrotoxicosis in children and adolescents causes a decrease in BMD and majorly increases the development of osteoporosis.

Physiological basis for absorptive and renal hypercalciurias

1979 ◽  
Vol 237 (6) ◽  
pp. F415-F423 ◽  
Author(s):  
C. Y. Pak
Keyword(s):  
Parathyroid Hormone ◽  
Calcium Absorption ◽  
Idiopathic Hypercalciuria ◽  
Calcium Balance ◽  
Physiological Basis ◽  
Dihydroxyvitamin D ◽  
Renal Tubular Reabsorption ◽  
Renal Tubular ◽  
Absorptive Hypercalciuria ◽  
Renal Hypercalciuria

Idiopathic hypercalciuria constitutes two major variants-absorptive hypercalciuria, characterized by a primary intestinal hyperabsorption of calcium, and renal hypercalciuria, in which renal tubular reabsorption of calcium is primarily impaired. The two forms of hypercalciuria may be distinguished from each other, since a) parathyroid function is stimualted in renal hypercalciuria, but normal or suppressed in absorptive hypercalciuria, b) the renal leak of calcium is present in renal hypercalciuria, but not in absorptive hypercalciuria, c) intestinal calcium absorption is probably increased primarily in absorptive hypercalciuria, and secondarily in renal hypercalciuria (from parathyroid hormone excess), d) the increased calcium absorption in renal hypercalciuria probably results from the parathyroid hormone-dependent stimulation of 1,25–dihydroxyvitamin D synthesis, whereas that in absorptive hypercalciuria may be vitamin D-independent, e) the response of the two conditions to certain treatments is unique, and f) the sequelae of parathyroid hormone excess, such as low bone density and negative calcium balance, may be present in renal hypercalciuria, but not in absorptive hypercalciuria. These findings provide a physiological basis for the consideration of absorptive and renal hypercalciurias as distinct and separate entities.

Prebiotic to Improve Calcium Absorption in Postmenopausal Women After Gastric Bypass: A Randomized Controlled Trial

2021 ◽  
Author(s):  
Karin C Wu ◽  
Sisi Cao ◽  
Connie M Weaver ◽  
Nicole J King ◽  
Sheena Patel ◽  
...  
Keyword(s):  
Gastric Bypass ◽  
Bone Turnover ◽  
Postmenopausal Women ◽  
Bone Turnover Markers ◽  
Calcium Absorption ◽  
Controlled Trial ◽  
Corn Fiber ◽  
Microbial Composition ◽  
Calciotropic Hormones ◽  
Turnover Markers

Abstract Context The adverse skeletal effects of Roux-en-Y gastric bypass (RYGB) are partly caused by intestinal calcium absorption decline. Prebiotics, such as soluble corn fiber (SCF), augment colonic calcium absorption in healthy individuals. Objective We tested the effects of SCF on fractional calcium absorption (FCA), biochemical parameters, and the fecal microbiome in a post-RYGB population. Design, Setting, Participants : Randomized, double-blind, placebo-controlled trial of 20 postmenopausal women with history of RYGB mean 5 years prior. Intervention 2-month course of 20 g/day SCF or maltodextrin placebo orally. Main Outcomes Between-group difference in absolute change in FCA (primary outcome) was measured with a gold-standard dual stable isotope method. Other measures included tolerability, adherence, serum calciotropic hormones and bone turnover markers, and fecal microbial composition via 16S rRNA gene sequencing. Results Mean FCA ±SD at baseline was low at 5.5±5.1%. Comparing SCF to placebo, there was no between-group difference in mean (95% CI) change in FCA (+3.4 [-6.7,+13.6]%), nor in calciotropic hormones or bone turnover markers. The SCF group had a wider variation in FCA change than placebo (SD 13.4% vs. 7.0%). Those with greater change in microbial composition following SCF treatment had greater increase in FCA (r 2=0.72,p=0.05). SCF adherence was high, and GI symptoms similar between groups. Conclusions No between-group differences were observed in changes in FCA or calciotropic hormones, but wide confidence intervals suggest a variable impact of SCF that may be due to the degree of gut microbiome alteration. Daily SCF consumption was well-tolerated. Larger and longer-term studies are warranted.

Modulation of the Anabolic Effect of Synthetic Human Parathyroid Hormone Fragment-(1-34) in the Bone of Growing Rats by Variations in the Dosage Regimen

1993 ◽  
Vol 85 (2) ◽  
pp. 223-228 ◽  
Author(s):  
Jean-Luc Riond
Keyword(s):  
Body Weight ◽  
Parathyroid Hormone ◽  
Calcium Absorption ◽  
Dry Weight ◽  
Vehicle Control ◽  
Intestinal Calcium Absorption ◽  
Calcium Balance ◽  
Anabolic Effect ◽  
Dihydroxyvitamin D3 ◽  
Female Wistar Rats

1. The influence of the time of the day of the administration of synthetic human parathyroid hormone fragment-(1-34) [hPTH-(1-34)] on its anabolic effect in bone was investigated in 23 60-day-old female Wistar rats. Rats were randomly assigned to the groups vehicle control morning, hPTH-(1-34)-treated morning, vehicle control afternoon and hPTH-(1-34)-treated afternoon, and once daily received a subcutaneous injection of 8 μg of hPTH-(1-34)/100 g body weight for 11 days. The increase in net intestinal calcium absorption and the increase in calcium balance were not influenced by the time of day of hPTH-(1-34) treatment. Four days after cessation of treatment, the net intestinal calcium absorption and calcium balance in hPTH-(1-34)-treated rats were not different from those of the control rats. 2. Modulation of the anabolic effect by variation of the hPTH-(1-34) dosage regimen was investigated in 43 60-day-old female Wistar rats. Rats were randomly assigned to the groups vehicle control, environmental control, 8 μg of hPTH-(1-34)/100 g body weight every 3 days for 24 days, 8 μg of hPTH-(1-34)/100g body weight every 2 days for 16 days, 8 μg of hPTH-(1-34)/100 g body weight every day for 8 days, 4 μg of hPTH-(1-34)/100 g body weight twice a day for 8 days and 2.7 μg of hPTH-(1-34)/100 g body weight three times a day for 8 days. In all cases, the total dose of hPTH-(1-34) received was 64 μg/100g body weight. Net intestinal calcium absorption and calcium balance increased significantly in the groups that received hPTH-(1-34) once a day, twice a day and three times a day. In relation with increased frequency of dosing, a significant linear trend existed for the increase in net intestinal calcium absorption and calcium balance. The hPTH-(1-34)-induced increase in total tibia calcium, total vertebrae calcium, tibia dry weight and vertebrae dry weight also tended to be more pronounced with more frequent dosing, although the trend was not significant. 3. Thus, smaller intervals between doses of hPTH-(1-34) enhance the anabolic response in bone despite the smaller doses. This effect may be secondary to 1,25-dihydroxyvitamin D3-induced increased intestinal calcium absorption, decreased 1,25-dihydroxyvitamin D3-induced bone resorption, up-regularion of osteoblast receptors for parathyroid hormone, or a combination of these three factors.

Role of Vitamin D and Parathyroid Hormone in the Regulation of Bone Turnover and Bone Mass in Men: The MINOS Study

2003 ◽  
Vol 73 (6) ◽  
pp. 520-530 ◽  
Author(s):  
P. Szulc ◽  
F. Munoz ◽  
F. Marchand ◽  
M. C. Chapuy ◽  
P. D. Delmas
Keyword(s):  
Vitamin D ◽  
Parathyroid Hormone ◽  
Bone Mass ◽  
Bone Turnover

A CASE OF PRIMARY HYPERPARATHYROIDISM WITH PARATHYROID HORMONE ASSAY IN URINE AND ADENOMA TISSUE

1963 ◽  
Vol 43 (2) ◽  
pp. 161-169
Author(s):  
Isaharu Miki ◽  
Seizo Yoshikawa ◽  
Satoru Takada ◽  
Takuo Fujita ◽  
Hirotoshi Morii
Keyword(s):  
Parathyroid Hormone ◽  
Serum Alkaline Phosphatase ◽  
Bone Tumour ◽  
Calcium Content ◽  
Calcium Balance ◽  
Lower Pole ◽  
X Ray ◽  
Parathyroid Hormone Assay ◽  
Adenoma Tissue ◽  
The Right

ABSTRACT A 42 year old male complained of limping and pain in the left leg, where a bone tumour was demonstrated by X-ray. Serum calcium was 11.2 to 15.2 mg% serum P 1.5 to 1.9 mg%, and serum alkaline phosphatase 8.7–10.4 Bessy-Lowry units. A markedly negative calcium balance was corrected by a diet high in calcium content. A parathyroid adenoma was removed from the right lower pole of the thyroid. The tumour possessed parathyroid hormone-like activity corresponding to 1580 USP units per gram of wet tissue and preoperative urine contained 65 and 97 units/24 hours according to the bioassay by 32P excretion method in parathyroidectomized rats. Postoperatively biochemical changes were normalized and recalcification of the skeleton was demonstrated.

Fluoride Therapy and Parathyroid Hormone Activity in Osteoporosis

1990 ◽  
Vol 79 (3) ◽  
pp. 233-238 ◽  
Author(s):  
T. C. B. Stamp ◽  
P. W. Saphier ◽  
N. Loveridge ◽  
C. R. Kelsey ◽  
A. J. Goldstein ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Parathyroid Hormone ◽  
Sodium Fluoride ◽  
Serum Alkaline Phosphatase ◽  
Biologically Active ◽  
Calcium Balance ◽  
Hormone Activity ◽  
Cross Sectional ◽  
Parathyroid Hormone Activity

1. To determine the relationships between parathyroid hormone activity and long-term sodium fluoride therapy in osteoporosis, cytochemical bioassays (for biologically active parathyroid hormone) were performed in 22 osteoporotic control patients and in 18 patients after 15 ± 10 months of treatment (60 mg of sodium fluoride daily). Ten patients were studied longitudinally by repeated metabolic balances and were therefore common to both groups. All patients were receiving mineral supplements. 2. Cross-sectional data showed a fourfold mean increase in biologically active parathyroid hormone on fluoride treatment (P < 0.005) together with a 51% increase in serum alkaline phosphatase (P < 0.005). Longitudinal data showed, in addition, a significant increase in the calcium balance of 2.4 ± 1.2 (sem) mmol daily (P < 0.05) and the development of a positive phosphorus balance (P < 0.02). 3. Fluoride-treated patients were then analysed in two groups according to the level of biologically active parathyroid hormone. Thirty-two per cent of values were above the upper limit of normal (18 pg/ml). The mean serum alkaline phosphatase level in this group showed no elevation above that of the control patients, the overall rise being accounted for entirely by patients with normal levels of biologically active parathyroid hormone. High levels of biologically active parathyroid hormone were also associated with relative hypophosphataemia (P < 0.01), relative hypercalciuria (P < 0.05) and an increased urine/faecal calcium ratio (P < 0.025). 4. Results show that long-term fluoride and calcium therapy increase biologically active parathyroid hormone in osteoporosis and that excessive parathyroid hormone activity may account for certain features of the refractory state.

scholarly journals Altered Mechanosensitivity Can Explain the Substantially Increased Bone Mass in Hypoparathyroidism

2011 ◽  
Author(s):  
Patrik Christen ◽  
Bert van Rietbergen ◽  
Keita Ito
Keyword(s):  
Parathyroid Hormone ◽  
Bone Mass ◽  
Bone Turnover

Hypoparathyroidism (HypoPTH) is characterized by low or absent parathyroid hormone (PTH). It is mainly associated with a drastic suppression of bone turnover by around 80% (Rubin et al., 2008) and a substantial increase in bone mass in the range of 10–32% (Rubin et al., 2008; Abugassa et al., 1993).

Sign in / Sign up

Export Citation Format

Share Document