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)

There is not yet an ideal marker of bone formation, but circulating BGP is the most satisfactory at present. New developments include the use of sheep BGP64 and human BGP85 as an immunogen and monoclonal antibodies, which may recognize fragments of BGP released during resorption. The specific measurement of bone alkaline phosphatase and the assay of procollagen fragments and of other noncollagenous bone-related proteins will allow a more precise assessment of the complex osteoblastic functions in normal and pathologic conditions. Finding a sensitive and specific marker of resorption is a challenge because all constituents of bone matrix are likely to be degraded into minute peptides during osteoclastic bone resorption. The measurement of pyridinium crosslinks and possibly of tartrate-resistant acid phosphate by a bone-specific monoclonal antibody are the most tangible improvements in this area. These markers need to be validated by comparison with data obtained by direct measurement of bone turnover on iliac crest biopsy. It should be remembered, however, that circulating markers reflect the overall activity of the whole skeleton, including the cortical, subcortical, and trabecular envelopes, which have different remodeling rates in normal and abnormal states. A circulating marker will not detect a specific defect of the cellular activity of one compartment of bone if the summated turnover of the skeleton is unchanged. Conversely, bone histomorphometry is limited to a small area of the trabecular envelope but allows detection of a specific defect at the cellular level. These differences should be kept in mind, as there is growing evidence that, for example, bone mass and bone turnover of osteoporotic patients before and during treatment vary in different appendicular/axial and cortical/trabecular compartments. Finally, a single marker might be valuable in some diseases and not in others (such as serum BGP in Paget's disease of bone). Despite these difficulties, significant advances have been made in the last few years in the bone marker field. In the future, the development of a battery of several bone-specific markers that indicate various aspects of the complex mechanisms of bone formation, resorption, and mineralization is likely to provide new tools for the diagnosis and management of bone diseases.
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PMID:Biochemical markers of bone turnover for the clinical assessment of metabolic bone disease. 219 65

The purpose of this study was to determine the value of calcium pidolate in the treatment of involutional osteoporosis. This compound has been reported to be better absorbed than other calcium salts, to lower the levels of parathyroid hormone (PTH) and to raise those of growth hormone (GH). We accordingly treated one group of 10 women suffering from involutional osteoporosis with the equivalent of 1 g elemental calcium and administered a placebo to a second group of 10 osteoporotic women whose mean age and body surface area were comparable. Basal sequential multiple analysis (SMA-12) was performed in all subjects to determine calcium, phosphorus, alkaline phosphatase (ALP) and total protein levels, the same blood samples being used for the evaluation of mean PTH, GH and osteocalcin (BGP). Urinary 24-h calcium excretion was determined and the calcium/creatinine (Ca/Cr) and hydroxyproline/Cr (HP/Cr) ratios were measured in 12-h fasting urine samples, the results being corrected for glomerular filtrate. The same parameters were measured again following a month of uninterrupted treatment. After 30 days, we observed no differences in either group as regards calcaemia, phosphataemia, ALP, total proteins, PTH, GH, BGP or 24-hour calciuria. The only noteworthy changes seen were significant decreases (P less than 0.001) in the Ca/Cr and HP/Cr ratios in the group treated with calcium pidolate. These results show that calcium pidolate at the dose administered inhibits bone resorption but does not affect the levels of PTH, GH, BGP or ALP in the medium term. Our findings indicate that it has no influence on bone formation.
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PMID:Effect of calcium pidolate on biochemical and hormonal parameters in involutional osteoporosis. 225 62

A study was undertaken in 46 subjects; 21 patients diagnosed as having HRL and 25 volunteers patients. Biochemical and hormonal analyses were performed in the study population, including determination of Ca, P, Mg, Cr in blood and urine, phosphate tubular resorption (PTR), maximum tubular phosphate resorption (MTPR), fasting calcium secretion (FCS), alkaline phosphatase (AP), hydroxyprolinuria (HPR), osteocalcin (BGP), parathormone (PTH), cAMP, and 1-25(OH)2D. The stone formers showed lower calcemia values (p less than or equal to 0.005d), higher phosphaturia, and magnesiuria (p less than or equal to 0.0005), higher FCS (P less than or equal to 0.005) and higher values for PTH (p less than or equal to 0.01) and cAMP (p less than or equal to 0.0025). No significant differences were observed for the other parameters evaluated. Classification of the patient group into 2 subgroups (renal SbR and absorptive SbA) according to FCS values greater or lower that 0.16 mg/dl, the SbR patient group revealed a higher PTH and 1-25(OH)2D values (p less than or equal to 0.05). There appears to be no increase of bone resorption since AP, HPR, and BGP values in our patients fell within normal ranges. The 1-25(OH)2D levels were also normal and, with respect to the control group, were only elevated for the SbR patient group, whose PTH levels were also observed to be elevated. These increments appear to be related and may result in intermediate forms between renal and absorptive hypercalciuria.
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PMID:[Parathormone, cyclic AMP, 1,25 dihydroxyvitamin D and osteocalcin in hypercalciuric renal lithiasis]. 254 53

We investigated the in vitro effect of corticosteroids on the responsiveness of human cells of osteoblast lineage to parathyroid hormone (PTH). Prior to corticosteroid treatment, the cells demonstrated only a small increase in cAMP production and no measurable change in transmembrane potential in response to PTH. Exposure of cells to dexamethasone resulted in a 5-fold increase in PTH-induced cAMP production and in measurable PTH-induced membrane depolarization in all cells studied. The effect of corticosteroids on cAMP production was specific for PTH (not seen with PGE1 or forskolin), occurred in a time- and dose-dependent fashion and in the absence of cell proliferation. Most of the cells were of osteoblast lineage as determined by the presence of alkaline phosphatase activity and BGP secretion. These findings further support the idea that corticosteroids increase the sensitivity of cells of osteoblast lineage to PTH, perhaps by transforming cells which initially have a low responsiveness to PTH to a state of high responsiveness.
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PMID:Corticosteroid-induced changes in the responsiveness of human osteoblast-like cells to parathyroid hormone. 254 39

Parathyroidectomy (PTx) is indicated in hemodialysis (HD) patients who have severe osteitis fibrosa unresponsive to vitamin D therapy or in whom the latter treatment is contraindicated. Immediately after PTx, plasma immunoreactive parathyroid hormone, calcium and phosphorus concentrations decline abruptly. However, little is known in such patients about the short-term effects of PTx on plasma alkaline phosphatase (AP) activity and plasma aluminum (Al) levels. The present, preliminary study was performed to determine such parameters in 37 HD patients, and to correlate them with data of bone histology. Mean plasma AP activity started to increase after PTx from day 4 onwards. Thus, AP values significantly higher than pre-PTx values were observed at day 7 and 14 (415 +/- 54 vs. 619 +/- 77 and 749 +/- 83 IU/liter, means +/- SEM; N = 37; P less than 0.05 and 0.001, respectively). This increase, in the absence of changes in liver function, was mainly due to the bone-specific iso-AP. Moreover, the degree of increase in plasma AP activity was higher in the subgroup with negative (group I, 21 patients) than in that with positive bone Al staining (group II, 16 patients). However, plasma osteocalcin (BGP) did not change after PTx (N = 8). Basal plasma Al levels were significantly higher in group II both before and two weeks after surgery.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Short-term effects of parathyroidectomy on plasma biochemistry in chronic uremia. 257 18

This study was performed in order to evaluate the clinical usefulness of the measurement of total serum alkaline phosphatase activity (AP), serum osteocalcin (BGP) and urinary hydroxyproline (OHPr) in assessing bone remodelling in primary hyperparathyroidism. Thirty-two patients with primary hyperparathyroidism were included in the study. No statistically significant differences were observed between the mean values of Z-scores obtained for each marker. Furthermore, an inverse correlation was found between percentage of bone mineral content at the distal radius and both BGP (r = -0.57; p less than 0.05) and AP (r = -0.49; p less than 0.05). The results obtained demonstrate that, contrary to other metabolic bone diseases (e.g. Paget's disease of bone), all three markers examined may be used in clinical practice to evaluate the entity of skeletal turnover in primary hyperparathyroidism.
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PMID:Clinical value of the measurement of bone remodelling markers in primary hyperparathyroidism. 259 39

Several bone abnormalities, characterized by a decreased bone turnover, may develop in patients with hypothyroidism. We have used the measurement of serum Osteocalcin (BGP), a protein synthesized by osteoblasts and proposed as a marker of bone formation, in order to elucidate the bone status in 62 hypothyroid patients, mean age 52 +/- 15 (SD) years. As a group, BGP results in hypothyroidism were not different from normal (3.6 +/- 3.2 vs 3.7 +/- 1.3 ng/ml). However, we were able to differentiate 3 groups: 1) patients with significantly lower BGP values (p less than 0.01) (primary hypothyroidism and total thyroidectomy with body scan); 2) patients with antithyroid drugs had significantly higher BGP levels (p less than 0.05); 3) in the other groups (post-1311, post-surgery, and insufficiently treated hypothyroidism) BGP values were within normal limits. In the total group BGP was significantly correlated with T3T, TSH, alkaline phosphatase and age. Lower serum BGP values in some etiologic groups of hypothyroidism may reflect a greater pathologic effect on the bone in these patients, with a decrease in bone formation.
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PMID:[Study of bone involvement in hypothyroidism determining the blood levels of osteocalcin]. 262 48

Calcium homoeostasis and bone mineralization have been the subject of many studies, but few have dealt with these aspects specifically in puberty. The main observations in our own studies - together with those in other recent reports - are summarized below. According to the aims of the present survey (Chapter 1) the results are grouped as follows: BLOOD MINERAL HOMOEOSTASIS AND ALKALINE PHOSPHATASE. The serum concentrations of calcium, total or ionized, remain remarkably constant throughout puberty, which probably reflects the important functions of the calcium ion. Serum phosphate, however, remain high in childhood, increase slightly with acceleration of growth and pubertal development and the levels then decrease toward adult values. Consequently, the pattern of the product of serum calcium and phosphate, essential for mineralization, follows that of phosphate. Serum magnesium does not change during puberty. The serum concentrations of alkaline phosphatase increase with acceleration in linear growth and pubertal development which has to be taken into consideration, in evaluation of changes in serum AP. Changes in osteoblastic activity, as expressed by AP (and BGP), are closely associated with changes in testosterone secretion with almost simultaneous increases in serum levels of both variables. It is further concluded that longitudinal study designs may add to the understanding of the growth process and rate of changes, whereas cross-sectional data are relevant to establish proper reference ranges. BONE MINERAL CONTENT. The use of photon absorptiometry in determining BMC is a precise, easy, atraumatic and reproducible method. It is shown that forearm BMC has a highly significant correlation to total body bone mineral also in the pubertal period of rapid growth. It should be noted that single measurements of BMC are of little diagnostic value in the presence of wide biological variation. A spurt in mineralization corresponding to that of height in puberty has been known since the development of the BMC technique. It is evident from our data that BMC and indices of body size are only significantly related after the start of the growth spurt. Significant increases of 25% in the BMC have been found in the year prior to PHV progressing with each PH stage. The mean time of maximal increase in forearm BMC occurred some 5 months later than that of testosterone and AP, and changes in these three variables are closely interrelated. The change in the serum concentrations of the two major adrenal androgens did not appear to be related to BMC.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Calcium homeostasis and mineralization in puberty. 265 Oct 27

Serum osteocalcin (bone gla protein, BGP), a vitamin K-dependent non-collagenous bone protein and its relationship to other markers of bone and mineral metabolism were studied cross-sectionally in varying numbers of patients before and over 240 days following renal transplantation. Marked elevation of serum creatinine (11.9 +/- 0.76 mg/dl), osteocalcin (216.9 +/- 7 ng/ml), parathyroid hormone (PTH, mid-molecule fragment) (24.5 +/- 3.6 ng/ml), alkaline phosphatase (255.2 +/- 54.7 IU/l) and phosphorus (5.6 +/- 0.3 mg/dl) were noted preoperatively. Serum calcium levels remained normal throughout the study period while phosphate levels normalized within one week after transplantation. PTH levels progressively decreased postoperatively over the study period but were still elevated well above normal. Serum osteocalcin decreased to near normal values at 60-90 days after surgery. Both PTH and alkaline phosphatase correlated significantly with osteocalcin preoperatively and postoperatively. The relatively depressed values of osteocalcin in the face of still elevated PTH levels post-transplantation was attributed to the effect of immunosuppressive corticosteroid therapy. The significant correlation between PTH and osteocalcin suggests that osteocalcin may be as or more sensitive a measurement of bone turnover than alkaline phosphatase pre- and post-transplantation.
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PMID:Serum osteocalcin and bone mineral metabolism following successful renal transplantation. 266 93

Serum levels of total alkaline phosphatase activity (S-T-AP), wheat germ lectin-precipitated alkaline phosphatase activity (S-L-AP), and bone Gla-protein immunoreactivity (S-BGP) were measured in 26 patients (23 females and 3 males) aged 35-73 years (mean 59 years) with primary hyperparathyroidism (n = 7), hyperthyroidism (n = 9), and hypothyroidism (n = 10) in whom the bone mineralization rate (m) was determined by 47Ca-kinetics (continuously expanding calcium pool model). A weak positive correlation (r = 0.42, P less than 0.05) was found between S-T-AP and m, which in the range from 0-18 mmol Ca/day could be estimated with a standard error of 4.6 mmol/day. A closer correlation (r = 0.65, P less than 0.001) was found between S-L-AP and m which was estimated with an error of 3.9 mmol Ca/day. The AP activity in the supernatant showed no significant correlation to m (r = 0.11, P greater than 0.50). The highest correlation coefficient (r = 0.81, P less than 0.001) was found between S-BGP and m which could be predicted with an error of 3.4 mmol Ca/day. S-BGP showed a closer correlation to S-L-AP (r = 0.71, P less than 0.001) than to S-T-AP (r = 0.58, P less than 0.01). We concluded that S-L-AP predicts bone mineralization at organ level better than S-T-AP in selected metabolic bone disorders and that the supernatant activity shows no relation to bone turnover.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Efficacy of wheat germ lectin-precipitated alkaline phosphatase in serum as an estimator of bone mineralization rate: comparison to serum total alkaline phosphatase and serum bone Gla-protein. 233 29


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