Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.3.1 (alkaline phosphatase)
47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Cosmos 1887 biosatellite carried 10 male rats and 2 rhesus monkeys on its 12.5-day mission. Upon re-entry the Vostok vehicle overshot the designated landing site, which resulted in fasting of the animals for 42 h, exposure to cage temperatures of 12-15 degrees C, and 2 days delay in death of the rats. No overt untoward effects of the delayed recovery were apparent. Tissues from the rats were harvested by Soviet scientists, appropriately preserved, and provided to U.S. investigators. Flight rats grew more slowly and had larger adrenal glands than earth gravity controls. Analysis of plasma revealed increased concentrations of hepatic alkaline phosphatase, glucose, urea nitrogen, and creatinine in flight rats. In contrast, electrolytes, total protein, albumin, corticosterone, prolactin, and immunoreactive growth hormone levels were unchanged. However, testosterone concentration was marginally decreased after flight and thyroid hormone levels were suggestive of reduced thyroid function. Due to the possible effects of reentry and the delay in recovery of the animals, it is not clear what relationship postflight levels of plasma constituents bear to their concentrations in flight.
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PMID:Cosmos 1887 mission overview: effects of microgravity on rat body and adrenal weights and plasma constituents. 229 71

We used single-photon absorptiometry to assess forearm bone mineral content (BMC/BW) (arbitrary units normalized for bone width) at a proximal site (PBMC/BW) and at a more distal site (DBMC/BW) in 60 women treated with 25-50 micrograms T3 or 50-100 micrograms T4 for euthyroid goitre, in 13 untreated goitre patients, and in 2 controls matched for age and menopausal state for each goitre patient. BMC/BW was not significantly different between untreated goitre patients and controls. In 36 premenopausal patients, treated for 5.8 +/- 5.4 years (mean +/- SD) a slight decrease in PBMC/BW of about 5% compared to controls to controls was observed (PBMC/BW 1.42 +/- 0.19 vs 1.49 +/- 0.13, P less than 0.05). In 24 postmenopausal patients, treated for 10.0 +/- 5.8 year, a 20% deficit in BMC/BW compared to controls was found (DBMC/BW 0.80 +/- 0.18 vs 1.06 +/- 0.20, P less than 0.001 and PBMC/BW 1.14 +/- 0.20 vs 1.42 +/- 0.19, P less than 0.001). Biochemical indices of bone metabolism in 43 pre and post-menopausal patients and 43 controls showed in the patients a higher serum alkaline phosphatase activity (AP) (P less than 0.01 and P less than 0.05 and serum osteocalcin (NS and P less than 0.05). AP was negatively correlated with TSH levels and, in postmenopausal patients, with DBMC/BW and PBMC/BW. Our results suggest that treatment of euthyroid women with moderate doses of thyroid hormone increases bone turnover with clear adverse effects on bone mineral status in postmenopausal patients.
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PMID:Reduced forearm bone mineral content and biochemical evidence of increased bone turnover in women with euthyroid goitre treated with thyroid hormone. 240 Oct 91

Thyroid function was investigated in 123 yusho patients who were exposed to toxic levels of polychlorinated biphenyls (PCBs) 16 years ago. In yusho patients, compared with the patients without evidence of yusho or normal controls, the serum triiodothyronine (T3) and thyroxine (T4) levels were significantly higher, while thyroid stimulating hormone (TSH) levels measured by sensitive assay were normal. There was no difference in serum levels of albumin, alkaline phosphatase, total cholesterol, and thyroxine binding globulin (TBG) between the two groups and the prevalence of positive antithyroid autoantibodies was almost the same, suggesting that hyperthyroxinemia in yusho patients was not due to increased TBG binding or abnormal autoimmune mechanism. Serum free T4 levels, however, were not elevated, although T4/TBG ratio was significantly higher. The thyroid hormone levels were higher than normal value in 4 of 123 yusho patients but only 1 case had clinical symptoms such as excessive perspiration. Despite higher serum PCBs in yusho patients, there was no correlation between PCB levels and levels of T3, T4, or TSH. The present results suggest hyperthyroxinemia without obvious clinical symptoms in yusho patients long after exposure to PCBs.
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PMID:Thyroid function in "yusho" patients exposed to polychlorinated biphenyls (PCB). 312 Dec 98

Thyroid hormones are essential for cartilage growth and maturation. In order to assess their actions during different periods of skeletal development, [125I]-triiodothyronine (T3) binding capacity in epiphyseal cartilage and triiodothyronine concentrations in serum were quantitated in bovine fetuses of the second and third trimesters of gestation (equivalent to fetal sizes of 10-90 cm crown-rump (CR) length), and related to the alkaline phosphatase activities in the same cartilaginous tissues. Nuclear T3 binding levels, which were initially low during 10-30 cm CR, rose to a peak value (1.7 pmol/mg DNA) at the end of the second trimester (40-50 cm CR). Then, following a sharp decline at 50-60 cm CR, T3 binding rose to a moderate level in the later gestational period (60-90 cm CR). Serum total triiodothyronine rose transiently in fetuses of 30-50 cm CR to a peak level (34 ng/100 ml), and subsequently increased continuously in the later period (60-90 cm CR). Alkaline phosphatase activities measured in epiphyseal chondrocytes rose significantly in fetuses of 60-90 cm CR. The coincident rise of cartilage triiodothyronine binding capacity and serum circulating triiodothyronine levels in the late second trimester suggests that this thyroid hormone induces its own binding sites in bovine epiphyseal cartilage; the dramatic increase in the level of serum triiodothyronine during the third trimester of gestation is temporally related to the increase in alkaline phosphatase activity of chondrocytes, as well as other recognized developmental changes in the fetal bovine skeletal tissues.
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PMID:Gestational changes of thyroid hormone action in the developing fetal bovine epiphysis. 312 43

In order to elucidate the mechanism of increased alkaline phosphatase (AI-P) activity of bone origin in serum of patients with hyperthyroidism, the effects of thyroid hormone on mouse osteoblast-like cells (MC3T3-E1) were studied in vitro. Triiodo-L-thyronine (T3) and thyroxine (T4) produced a dose-dependent increase in AI-P activity in the cells at minimum concentrations of 10(-10)M T3 (free T3, 5 x 10(-12) M) and 10(-8) M T4 (free T4, 8 x 10(-11) M), respectively. Scatchard analysis revealed that MC3T3-E1 cells contained nuclear binding sites specific for T3 with an apparent Kd of 120 pM (maximum number of binding sites, approximately 2500 per cell). When cells were cultured with T3 in alpha-minimal essential medium (alpha-MEM) for a prolonged period, AI-P activity also became detectable in the conditioned medium. In contrast to rat osteosarcoma cells (ROS 17/2.8), MC3T3-E1 cell growth was inhibited by T4 in a concentration-dependent manner. These findings suggest that thyroid hormone inhibits proliferation and stimulates differentiation of mouse osteoblast-like cells. Since T3 and T4 stimulate AI-P activity not only in the cells but also in the medium, we speculate that the hyper-alkaline phosphatasia frequently seen in patients with hyperthyroid Graves' disease is partly due to a direct effect of thyroid hormone on osteoblasts or osteoblast-like cells.
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PMID:Stimulation of alkaline phosphatase activity by thyroid hormone in mouse osteoblast-like cells (MC3T3-E1): a possible mechanism of hyperalkaline phosphatasia in hyperthyroidism. 319 Dec 90

Selenium deficient calves when compared to selenium supplemented calves had increased plasma thyroxine concentrations and decreased plasma tri-iodothyronine concentrations. These changes in the selenium deficient calves were accompanied by significant increases in plasma urea and creatinine concentrations and decreased plasma alkaline phosphatase activity. The demonstration that low selenium status can cause imbalances in thyroid hormone metabolism may provide an explanation for some of the effects of the deficiency.
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PMID:Thyroid hormone concentrations in selenium deficient and selenium sufficient cattle. 322 43

The serum BGP level was assayed in patients with hyperthyroidism (untreated and remittent cases) and hypothyroidism. The mean serum BGP concentration was 9.7 +/- 0.90 ng/ml in 30 patients with untreated hyperthyroidism which was significantly higher than the 2.7 +/- 0.38 ng/ml in 15 remittent patients and 1.3 +/- 0.31 ng/ml in 13 patients with hypothyroidism (p less than 0.001, p less than 0.001). Serum BGP had a significant positive correlation with the concentrations of free triiodothyronine and alkaline phosphatase in the serum, while it had a significant negative correlation with serum PTH. In the patients with hypothyroidism, serum BGP increased significantly in parallel with increases in serum free triiodothyronine with thyroxine therapy. In the patients with hyperthyroidism, serum free triiodothyronine decreased significantly after the first month of methimazole treatment, and fluctuated within the normal range after two months. Serum alkaline phosphatase and BGP did not show significant changes during the first six months of treatment, although they were eventually reduced significantly at the end of one year. These results suggest that thyroid hormone directly stimulates the synthesis and secretion of BGP in existent osteoblasts and also acts on the bone remodeling cycle, therapy accelerating the rate of bone formation; the latter action may occur over a long period.
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PMID:Influence of thyroid function on serum bone Gla protein. 326 Aug 58

Serum bone Gla protein (BGP) concentrations were measured in 24 hyperthyroid patients before and after treatment. Before treatment, the mean concentration was higher [11.8 +/- 3.4 ( +/- SD) ng/ml] in the patient group than in a group of 12 age-matched normal subjects (6.1 +/- 1.7 ng/ml; P less than 0.001); 16 of the 24 patients had a value above the normal range. Serum BGP concentrations in the patients correlated significantly with serum T3 (r = 0.65; P less than 0.001) and T4 concentrations (r = 0.56; P less than 0.01). Other biochemical markers of bone metabolism (serum alkaline phosphatase, serum and urinary calcium, and urinary hydroxyproline) did not correlate with circulating thyroid hormone levels. Serum BGP also was measured after the patients had become euthyroid; 23 measurements were made on 16 patients at various times after the start of treatment. All values were normal after 16 weeks; before this period, most of the values were still above the normal range despite normal plasma thyroid hormone concentrations in all patients. These results suggest that BGP is a sensitive marker of bone metabolism alterations during hyperthyroidism.
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PMID:Serum bone Gla protein: a marker of bone turnover in hyperthyroidism. 348 49

To investigate the increased alkaline phosphatase activity of bone origin in patients with hyperthyroidism, we studied the thyroid hormone effects on alkaline phosphatase activity in a clonal rat osteoblastic cell line (ROS 17/2.8). T4 and T3 increased alkaline phosphatase activity in ROS 17/2.8 cells in a dose-dependent manner. The minimal effective T4 and T3 concentrations in medium containing 10% thyroid hormone-depleted fetal calf serum were 10(-8) M (free T4, 8 X 10(-11) M) and 10(-9) M (free T3, 4 X 10(-11) M), respectively. ROS 17/2.8 cells possessed high affinity, low capacity nuclear receptors specific for T3 [dissociation constant (Kd) approximately 150 pM; maximal binding capacity, approximately 2000 T3 binding sites per nucleus]. The relative affinity of T3, T4, rT3, MIT, and DIT were in good agreement with their biological activity. These findings suggest that rat osteoblast-like cells contain T3 nuclear receptors and that alkaline phosphatase activity is stimulated by thyroid hormone via a nuclear receptor-mediated process at free thyroid hormone concentrations attainable in patients with Graves' disease.
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PMID:Thyroid hormone stimulates alkaline phosphatase activity in cultured rat osteoblastic cells (ROS 17/2.8) through 3,5,3'-triiodo-L-thyronine nuclear receptors. 356 18

Mineral metabolism and bone histomorphometric status were evaluated in 31 hyperthyroid patients (HT) without clinical or radiological bone disease, both before and after treatment of hyperthyroidism. Blood and urine biochemical data were compared with those obtained in sex and age-matched controls. Iliac bone biopsies were available from 12 untreated HT and from 6 of them after treatment for analysis of trabecular bone. Mean plasma calcium was increased in HT but true hypercalcemia was seen in only one case and mean plasma immunoreactive parathormone (iPTH) was normal. Urine calcium excretion was markedly increased, especially in the fasting state. Biochemical parameters decreased after treatment, except for serum alkaline phosphatase and iPTH that, respectively, remained high and increased. Untreated state was characterized by an hyperremodelling state with enhanced activities of bone formation and bone resorption. Bone mineralization was normal. The mineral and bone changes were related to serum thyroid hormone levels. After treatment, the extent of formation surfaces still increased. The fact that, even though calcium metabolism abnormalities were corrected, active resorption surfaces did not change, suggests that trabecular osteoclastic resorption is not an important cause of mobilization of bone calcium to extracellular fluids in HT.
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PMID:Effect of thyrotoxicosis and its treatment on mineral and bone metabolism. 357 53


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