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)

We report 2 cases of true hypocalcemia (not caused by decreased binding proteins) associated with metastatic prostate cancer and review previously reported cases. Hypocalcemia is a common but frequently unrecognized complication of prostatic cancer. Estrogen therapy often is associated with the hypocalcemia, which may be asymptomatic. The hypocalcemia is always associated with osteoblastic metastases and usually it is associated with increased serum alkaline phosphatase activity, acid phosphatase activity and serum parathyroid hormone concentration. Serum concentrations of magnesium, phosphorus and vitamin D frequently are decreased. Patients are in a positive calcium balance. The osteoblastic metastases seem to act as a calcium sink, creating a "hungry tumor phenomenon". The role of estrogens may be to stop the resorption of normal bone resulting in lower serum calcium concentrations.
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PMID:Hypocalcemia associated with estrogen therapy for metastatic adenocarcinoma of the prostate. 317 54

This study concerns the effect of graded doses of estrogen, alone or in combinations with progesterone, on the biochemical composition of the rat seminiferous tubules. Data on the accessory genital organs and pituitary gonadotrophic activity are added. Adult male albino rats received estradiol dipropionate (.1, 1 and 5 mcg/rat) injected intramuscularly, in .1 ml olive oil, daily for 30 days. Animals given the 5 mcg dose were given a 30 day rest period to determine reversibility of effects. In another group estrogen (5 mcg/rat) and progesterone (1 mg/rat) were given concurrently but at different sites for 30 days. Controls received vehicle only. Animals were sacrificed 24 hours after the last injection or rest period and genital organs and the pituitary were removed for study. A progessive reduction in testis weight with dosage was found after estrogen or the combination (p is less that .01). The low dose (.1mcg) had an inconsistent effect on spermatogenesis and endocrine function of the testis. Diameter of the tubules was reduced. Spermatogenesis was arrested in 25% of the tubules at the spermatid of secondary spermatocyte stage. Some normal spermatozoa were seen. Tunica propria was thickened. Some Leydig cells showed atrophy. Vascularity was increased. The median dose (1 mcg) caused spermatogenic arrest at the spermatid or secondary spermatocyte stage but the Sertoli cells were prominent. Only a few spermatozoa were seen. There was some desquamation of seminiferous epithilium. Tubular diameter was still further reduced and the tunica propria thickened. Leydig cells were atrophied. Few spermatozoa were found although 25-30% showed some spermatogenesis. The high dose (5 mcg) caused marked reduction in the diameter of the tubules. Spermatogenesis was arrested at the primary spermatocyte or spermatogonial stage. The tunica popria was much thickened. There was much desquamation and tubular lumeus were filled with debris. The Sertoli cells were hypertrophied. The Leydig cells were atrophied. The tunica albuginea was thickened. There were no spermatozoa. In the recovery group estrogen effects had disappeared, but the tubular diameter remained reduced. Tunica propria was normal. Spermatogenesis progressed to the spermatid stage and in 50% of the tubules many spermatozoa were present. The Leydig cells appeared normal. However spermatozoa were not found in the vas defereus. The histological appearance of the teatis in the estrogen and progesterone group was of the high dose estrogen type but with arrest of spermatogenesis at the spermatid, spermatocye or spermatogonial stage. The Sertoli cells remained hypertrophied. Leydig cells were atrophic. The large blood vessels were engorged. Weight of organs returned almost to normal. Estrogen .1 and 1 mcg had no effect on pituitary weight or gonadotrophin content. The high dose (5 mcg) alone or with progesterone caused a significant increase in pituitary weight (p is less than .0). Estrogen alone (5 mcg) caused a significant decline in pituitary gonadotrophin content (p is less than .0) but the combined therapy had no effect. None of the biochemical constituents of the seminiferous tubules showed any change after injection of .1 mcg of estrogen but 1 mcg dose caused an increase in protein nitrogen, alkaline phosphatase activity and total lipids. The high dose (5 mcg) provoked higher levels.
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PMID:Effect of estrogen on biochemical composition of the rat seminiferous tubules. 514 19

In vitro cultivated cells derived from normal human renal cortex were characterized morphologically and biochemically. Although the epithelial monolayer was composed of heterogeneous cells, it included cells with a surface structure similar to microvilli as well as some resembling the desmosome between neighboring cells. Enzymatic studies revealed a marked decrease in alkaline phosphatase activity, and the activity of gamma-glutamyl transpeptidase was also reduced to about one-fifth of that in the original tissue. The electrophoretic mobility of the enzyme was not identical with that of normal kidney or of the novel enzyme in renal neoplastic tissue. Lactate dehydrogenase activity was similar to that of normal kidney tissue but the isozyme pattern was completely inverted. These cells responded to the addition of 10 ng per ml of parathyroid hormone in culture medium and there was a 33 fold increase in intracellular cyclic adenosine monophosphate. Estrogen specific binding protein was not detectable in the monolayer cells. These results clearly indicated that the biologic transformation observed in the cultivated normal cells was not attributable to simple fetalism or dedifferentiation, but was a more complicated process.
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PMID:Morphologic and biochemical characteristics of human kidney cells in vitro. 611 28

Fourteen postmenopausal women with mild hyperparathyroidism were given conjugated estrogens. Serum calcium levels became normal and urinary calcium excretion was reduced for up to 2 years in ten patients taking an average dose of 1.25 mg of estrogen daily. Hypercalcemia returned quickly when therapy was interrupted. Estrogen did not systematically alter serum immunoreactive parathyroid hormone or calcitriol levels or urinary excretion of cyclic adenosine monophosphate. Significant reductions in urinary hydroxyproline and serum alkaline phosphatase activity during estrogen therapy indicate that the major effect of therapy was to decrease bone turnover. Iliac crest biopsy specimens taken before estrogen therapy showed normal trabecular bone volume and excessive osteoid seams. Follow-up biopsy specimens were taken from six patients after 1 year on therapy. Bone volume remained stable, but hyperosteoidosis had improved in only one patient. Without understanding the long-term impact of untreated mild hyperparathyroidism on bone, the benefits of estrogen therapy on bone remain uncertain. However, therapy with conjugated estrogens provides sustained control of serum and urine calcium in most women with hyperparathyroidism and is a reasonable alternative in patients who are not surgical candidates.
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PMID:Conjugated estrogens in the treatment of postmenopausal women with hyperparathyroidism. 632 24

The associations of current oral contraceptive (OC) or estrogen use and mean levels of a variety of clinical chemistry measurements have not been previously described in large, free-living populations. We compared mean fasting measurements of eight clinical chemistry tests (alkaline phosphatase, serum glutamic oxaloacetic transaminase [SGOT], total bilirubin, globulin, thyroxine, creatinine, uric acid and plasma glucose) adjusted for age, body mass, education, alcohol use, smoking and study population variation in approximately 1,500 white women from nine North American Lipid Research Clinic populations. Compared to hormone nonusers of the same age, OC users aged 20 to 39 years had significantly lower mean values of serum alkaline phosphatase, SGOT, total bilirubin and plasma glucose, while serum globulin, thyroxine and creatinine levels were significantly higher. Mean uric acid values were not significantly different. Estrogen users aged 50 to 69 years had significantly lower mean values of alkaline phosphatase and total bilirubin and significantly higher thyroxine and uric acid levels as compared to hormone nonusers aged 50 to 69 years.
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PMID:Alterations in clinical chemistry measures associated with oral contraceptive and estrogen use: the Lipid Research Clinics Program Prevalence Study. 710 63

The efficacy of commercially available progestin preparations were investigated with a view toward determining the optimum type, dose, duration, and route of administration required to protect the endometrium. Biochemical indices of estrogen and progestin action in endometria from postmenopausal women receiving various hormone therapies were monitored. The premenopausal samples obtained during the proliferative and secretory phases of the cycle can be compared with physiologically normal activities. Estrogen effects were monitored by nuclear estradiol receptor (REN) and soluble progesterone receptor (RP) content and DNA synthesis by autoradiography after [3-H]-thymidine labelling. Progestin action was assayed by inhibition of estrogen-induced REN and DNA synthesis by induction of isocritic and estradiol dehydrogenases and by morphological criteria. Postmenopausal patients were attending the menopause clinics at King's College Hospital or the Chelsea Hospital for Women in London for symptoms associated with the climacteric. Premenopausal samples were obtained from women attending the above hospitals as well as St. Thomas Hospital in London. There are no differences in REN or estradiol receptor content (RET) between epithelium and stroma for any of the groups. Progestins, regardless of whether they are derived from exogenous (postmenopausal) or endogenous (premenopausal sources, decrease REN and RET in both fractions. Progestins also decreased DNA synthesis in both cell types and this suppression correlates with the fall in REN. The RP content of epithelium is greater than stroma, but the 2 enzymes are markedly stimulated by progestins in epithelium but not stroma. The lower RP content of the stromal fraction could be because of cellular heterogeneity, differential loss of receptor during processing, or to genuine differences between epithelium and stroma. Estrogen induced DNA synthesis is inhibited by progestins in both epithelium ans stroma but the induction of some enzymes is dissimilar in the 2 cell populations. Marked increases in activity of isocitric and estradiol dehydrogenases take place in epithelium but not stroma under the influence of progestins. Enzymes such as acid and alkaline phosphatase do not exhibit this uneven cellular distribution. For the clinical studies on progestin effects, it was decided to analyze DNA synthesis, REN, and estradiol and isocritric dehydrogenase activities. All estrogenic medications in clinical use in the U.K. produce levels of REN and RP that are at least equivalent to those found in the proliferative phase of the premenopausal endometrium. No differences in REN, RP, or DNA synthesis were observed between the 0.625 and 1.25 mg doses of Premarin so it appears that even the low dose of estrogen is maximally stimulating the endometrium. The study results strongly indicate that the addition of a progestin to estrogen medication is efficacious in preventing continued cell multiplication of both epithelium and stroma. They also show that unnecessarily high doses of progestin are in current use.
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PMID:Assessment of oestrogen and progestin effects on epithelium and stroma from pre- and postmenopausal endometria. 733 44

Extracts of A. niger could catalyze sequential hydrolysis of the three phosphate moieties of the ATP molecule optimally at pH 2 and at pH 8. At pH 2 the hydrolysis was effected by an ATPase followed by acid phosphatase while at pH 8 alkaline phosphatase was the only involved enzyme. Separation of these three phosphate-hydrolyzing enzymes was achieved by Sephadex G-100 column chromatography. The A. niger ATPase seems to have two unique features. First, it was easily solubilized in distilled water and second it had optimum activity at pH 2. The activity of this enzyme was not affected on addition of Na+, K+ or Ca2+ to the assay reaction mixture. It was neither inhibited by sodium azide nor by potassium nitrate but inhibited by orthovanadate, DES, DCCD, Mg2+ and Pi. The substrate concentration-activity relationship was of the hyperbolic type. The enzyme had high specificity for ATP, was inert with ADP and its activity with GTP represented about 6% only of that obtained with equimolar amount of ATP.
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PMID:Participation of a proton-translocating plasma membrane ATPase, acid phosphatase and alkaline phosphatase in ATP degradation by Aspergillus niger extracts. 754 49

Estrogen receptors of human endometrial cancer Ishikawa cells were found to be present in moderate amounts (160-200 fmol/mg protein), and to specifically bind moxestrol (R2858) with a very high affinity characterized by a Kd around 60 pM, when measured under equilibrium conditions. The binding specificity respected a decreasing order as follows: estradiol (E2: 100%) > 4-hydroxy-tamoxifen (4OHTAM: 52.7%) > estriol (E3: 5.7%) > estrone (E1: 2.1%) > TAM (0.2%). The induction of alkaline phosphatase activity (APase) used as an estrogen-specific response, confirmed the intrinsic estrogenicity of progestins derived from 19-nor-testosterone (19NT): norethindrone (NOR), norethynodrel and levonorgestrel, at concentrations ranging from 10(-8) to 10(-6) M. The effect of NOR was partially blocked by the antiestrogen 4OHTAM, which was also partially agonistic in this model, but neither by the antiprogestin mifepristone (RU486) nor by the aromatase inhibitor aminoglutethimide. A simulatory effect was also detected at 10(-7) or 10(-6) M with ethindrone, the testosterone- (T) derived progestin homologous to NOR, and with both androgenic parent-compounds, i.e. T and 19NT themselves. In contrast, progesterone (P) derivatives like medroxyprogesterone acetate (MPA) and chlormadinone acetate (CMA) remained totally inactive, as well as 19-nor-progesterone (19NP) itself or its progestagenic derivatives: ORG 2058 and nomegestrol acetate (NOM). Structure-activity relationships deduced from these studies suggest that it is not the absence of the 19-methyl group which can account for the estrogenic potential of the so-called "19-norprogestins", but rather their steroid structure derived from T in a broad sense (including the 19NT derivatives), as opposed to the non-estrogenic therapeutic progestins derived from P like MPA or CMA, or from 19NP like NOM.
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PMID:Lack of estrogenic potential of progesterone- or 19-nor-progesterone-derived progestins as opposed to testosterone or 19-nor-testosterone derivatives on endometrial Ishikawa cells. 757 23

Estrogen has been shown to modify calcium and skeletal homeostasis. In this study, we tested the ability of estrogen to influence the effects of short-term 1,25(OH)2D administration on biochemical indices of bone formation and resorption in a cross-sectional analysis of untreated (n = 10) and estrogen-treated (n = 14) osteoporotic women. Patients were given oral 1,25(OH)2D (Rocaltrol) 0.5 microgram twice a day for 5 days. Serum and urine were sampled at baseline and then 1 h after the first daily Rocaltrol dose for the 5 days of the study. 1,25(OH)2D levels rose similarly in both groups with plateaus reached by the third day of the investigation. Serum PTH levels decreased by the first sampling period (1 h after first Rocaltrol dose; p < 0.008 both groups) and continued to fall gradually in both groups. There were no changes in serum calcium but serum phosphorus rose by the second day (p < 0.05 both groups) and remained elevated throughout the remainder of the protocol. Serum bone Gla protein increased approximately 40% (p < 0.05) with no group differences. In contrast, total alkaline phosphatase and carboxy-terminal propeptide of type I collagen did not increase in either group. Furthermore, there were no significant increments in any bone resorption indicators, including serum tartrate-resistant acid phosphatase and cross-linked carboxy-terminal telopeptide of type I collagen, as well as urine hydroxyproline and pyridinoline. Serum IGF-1 levels also remained unchanged in both groups. We conclude that oral 1,25(OH)2D administration decreased 1-84PTH levels, probably due to a suppression of parathyroid production, and did not stimulate bone resorption.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Oral 1,25-dihydroxyvitamin D administration in osteoporotic women: effects of estrogen therapy. 761 Sep 30

Estrogen replacement therapy (ERT) prevents bone loss and fracture in early postmenopausal women, but its benefit for women over 70 yr of age has not been determined. We have examined the effect of a short course of ERT on biochemical markers of bone turnover in older women. Eleven women (mean age, 77 yr) were given conjugated estrogen (Premarin; 0.625 mg/day) for 6 weeks. Biochemical markers were measured on serum and urine collected at baseline (two samples), after 5 and 6 weeks of ERT, and 5 and 6 weeks post-ERT. Markers of bone formation were osteocalcin, bone alkaline phosphatase, and type I procollagen peptide. Markers of bone resorption were total urinary hydroxyproline, total and free pyridinoline and deoxypyridinoline cross-links, type I collagen cross-linked N-telopeptides, and serum C-terminal cross-linked telopeptide. Data were analyzed by repeated measures multivariate analysis of variance to estimate the overall effect of ERT on the biochemical markers. Markers of bone resorption decreased during ERT and returned to baseline after ERT (P < 0.05). Markers of bone formation declined less during ERT and continued to decline after ERT (P < 0.05). We conclude that ERT reduces bone turnover in older women and that markers of bone turnover may be useful in assessing the response to treatment in this age group.
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PMID:The short-term effects of conjugated estrogen on bone turnover in older women. 804 49


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