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1.
Carlos Gregorio Silvina Eduardo Luis C. Rodrigues María A. Regueira Ramn Fraga Ricardo Riveiros Miguel Maestro Antonio Mourio 《The Journal of steroid biochemistry and molecular biology》2007,103(3-5):227
Hapten derivatives of 25-hydroxyvitamin D3 and 1α,25-dihydroxyvitamin D3 were synthesized using the Wittig–Horner approach. Both haptens bearing a carboxylic group at the side chain that can be linked to a protein for raising antibodies of potential utility for the determination of 25-hydroxyvitamin D3, 1α,25-dihydroxyvitamin D3 and 1α-hydroxylated vitamin D3 analogues. 相似文献
2.
Norihiro Kobayashi Hidetoshi Mano Tetsuya Imazu Kazutake Shimada 《The Journal of steroid biochemistry and molecular biology》1995,54(5-6)
We report here a novel and powerful pretreatment method for radioreceptor assays (RRAs) for human plasma 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3) based on “Tandem” immunoaffinity chromatography (Tandem IAC). Two antibodies having different specificities were each immobilized on agarose gel with cyanogen bromide to produce immunosorbents which were stable and repeatedly usable. An ethyl ether extract of plasma was applied to the first affinity column, from which 1,25(OH)2D3 could be preferentially eluted and separated from 1α-deoxy type metabolites. The effluent was then submitted to the second column, and the 1,25(OH)2D3 retained was eluted after non- or weakly-adsorbed interfering substances were washed out. This procedure allowed efficient purification without careful handling or strict time-management in the entire operation and enabled avoiding preparative high-performance liquid chromatography (HPLC) from RRA even with a conventional chick intestinal vitamin D receptor. Mean (± SD) plasma 1,25(OH)2D3 values of 56 normal subjects and 10 patients with chronic renal failure, obtained with this Tandem IAC/RRA system, were 36.4 (8.7) and 11.2 (4.0) pg/ml, respectively. The Tandem IAC will also be useful for developing immunoassays or gas chromatography-mass spectrometry of 1,25(OH)2D3. 相似文献
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The essential role of vitamin D throughout the life of most mammals and birds as a mediator of calcium homeostasis is well established. In view of the complex endocrine system existent for the regulated metabolism of vitamin D3 to both 1α,25-dihydroxyvitamin D3 [1,25(OH)2D3] and 24R,25-dihydroxyvitamin D3 [24R,25-(OH)2D3] (both produced by the kidney), an intriguing problem is to elucidate whether only one or both of these dihydroxyvitamin D3 metabolites is required for the generation of all the biological responses mediated by the parent vitamin D3. In contrast to the accumulated knowledge concerning the short term actions of 1,25(OH)2-D3 on stimulating intestinal calcium absorption and bone calcium reabsorption, relatively little is known of the biological function of 24,25(OH)2D3. We report now the results of a nine month study in which chicks were raised on a vitamin D-deficient diet from hatching to sexual maturity and received as their sole source of “vitamin D” either 24,25(OH)2D3 or 1,25(OH)2D3 singly or in combination. Specifically we are describing the integrated operation of the vitamin D endocrine system as quantitated by the individual measurement in all birds of 22 variables related to “vitamin D status” and as evaluated by the statistical procedure of multivariate discriminant analysis. Twelve of these variables involved detailed analysis of the bone including quantitative histology and the other 10 variables reflect various manifestations of vitamin D action, e.g. serum Ca2+ and Pi levels, vitamin D-dependent calcium binding protein (CaBP) in the intestine and kidney, egg productivity etc. As evaluated by the multivariate analysis, it is clear that 24,25(OH)2D3 and 1,25(OH)2D3 are simultaneously required for normalization of calcium homeostasis. 相似文献
5.
Kidney tubules obtained from chicks fed a high-calcium low-phosphorus diet retained 25-hydroxyvitamin D3-1-hydroxylase activity after a 10 h incubation in serum-free minimum essential medium. Inclusion of 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) in the medium prompted a suppression of 25-hydroxyvitamin D3-1-hydroxylase and the induction of 25-hydroxyvitamin D3-24-hydroxylase activities. The enzyme switch-over response could be prompted by 1.6 × 10?7 M 1,25-dihydroxyvitamin D3 and occurred within 6 h following treatment. Medium calcium appeared to augment the metabolite's switch-over action. 相似文献
6.
Metabolism of 25-[3H]hydroxyvitamin D3 was studied in peritoneal macrophages from renal failure patients on continuous ambulatory peritoneal dialysis (CAPD). Cells from 5 out of 8 patients with a history of peritonitis produced significant amounts of a metabolite chromatographically identical to 1 alpha,25(OH)2D3; but none was produced by cells from non-infected patients. The evidence strongly suggests that peritoneal macrophages stimulated by infection can metabolise 25OHD3 to the active vitamin D3 metabolite, 1 alpha,25(OH)2D3, when maintained in short-term primary culture. 相似文献
7.
Selective analogs of 1α,25-dihydroxyvitamin D3 for the study of specific functions of Vitamin D 总被引:1,自引:1,他引:0
Hector F. DeLuca Lori A. Plum Margaret Clagett-Dame 《The Journal of steroid biochemistry and molecular biology》2007,103(3-5):263
New analogs of 1α,25-dihydroxyvitamin D3 synthesized in our research group that show selective activity in vivo are presented along with supporting biological results. Compounds that act preferentially on intestine are 2-(3′-propylidene-19-nor-(20S or 20R))-1α,25-dihydroxyvitamin D3 and 2-methylene-19-21-dinor-1α,25-dihydroxyvitamin D3. Compounds that act anabolically to induce bone formation are 2-methylene-19-nor-(20S)-1α,25-dihydroxyvitamin D3 (2MD), the 2α-methyl derivative, the 26,27-dimethyl derivative, and the 26-dimethylene derivative. Compounds that act preferentially on parathyroid glands are 2-methylene-19-nor-1α-hydroxy-homopregnacalciferol, the 20S-bishomo derivative and the 2-methylene-19,26,27-trinor-1α,25-dihydroxyvitamin D3. These latter compounds do not elevate serum calcium until doses of the order of >300 μg/kg body weight are used, while parathyroid hormone levels are suppressed at much lower doses. Some of these novel analogs may ultimately be useful as new and safer therapeutic agents. Regardless of their clinical utility, they represent valuable research tools that can be used to study the specific functions of the Vitamin D hormone in vivo. 相似文献
8.
A. Verstuyf C. Mathieu L. Verlinden M. Waer B. K. Tan R. Bouillon 《The Journal of steroid biochemistry and molecular biology》1995,53(1-6):431-441
1,25(OH)2D3 and two stereoisomers of retinoic acid, all trans and 9-cis retinoic acid, are regulators of cell proliferation and differentiation. The aim of this study was to evaluate the effects of a combination of 1,25(OH)2D3 and retinoic acid (all trans or 9-cis) on proliferation and cell differentiation of the human promyelocytic leukemia cell line HL60, and to test the reversibility of the induced differentiation. Cell proliferation was inhibited as expected by 1,25(OH)2D3 and all trans retinoic acid alone (IC50 of cell survival was 4 × 10−7 M, 9 × 10−6 M and 9 × 10−7 M for 1,25(OH)2D3, all trans and 9-cis retinoic acid, respectively). Combination of 1,25(OH)2D3 and either form of retinoic acid resulted in a partially additive decrease in cell proliferation. 1,25(OH)2D3 induced a monocytic differentiation (100% CD14+ cells with 10−7 M 1,25(OH)2D3), while retinoic acid led to a predominantly granulocytic differentiation (36 and 42% CD67+ cells with 10−6 M all trans and 9-cis retinoic acid, respectively). Additive effects on differentiation were observed upon combination of subtherapeutical doses of the drugs, achieving a mainly monocytic population, demonstrating the dominant role of 1,25(OH)2D3 in determining the direction of differentiation. The effects on proliferation and differentiation of the solitary drugs were reversible, while the proliferation arrest and differentiation induced by the combination persisted and even progressed after withdrawal of the drugs. We conclude that 1,25(OH)2D3 and retinoic acid (all trans or 9-cis) exert additive effects on inhibition of proliferation and induction of cell differentiation of HL60 cells, leading to a persistent differentiation, even after drug withdrawal. 相似文献
9.
T.C. Chen K.S. Persons S. Zheng J. Mathieu M.F. Holick Y.F. Lee B. Bao M.A. Arai A. Kittaka 《The Journal of steroid biochemistry and molecular biology》2007,103(3-5):717
1α,25-Dihydroxyvitamin D3 (1α,25(OH)2D3) is known to inhibit the proliferation and invasiveness of prostate cancer cells. However, 1α,25(OH)2D3can cause hypercalcemia and is not suitable as a therapeutic agent. 19-Nor-vitamin D derivatives are known to be less calcemic when administered systemically. In order to develop more potent anti-cancer agents with less calcemic side effect, we therefore utilized 3H-thymidine incorporation as an index for cell proliferation and examined the antiproliferative activities of nine C-2-substituted 19-nor-1α,25(OH)2D3 analogs in the immortalized PZ-HPV-7 normal prostate cell line. Among the nine analogs we observed that the substitution with 2α- or 2β-hydroxypropyl group produced two analogs having antiproliferative potency that is approximately 500- to 1000-fold higher than 1α,25(OH)2D3. The 3H-thymidine incorporation data were supported by the cell counting data after cells were treated with 1α,25(OH)2D3, 19-nor-2α-(3-hydroxypropyl)-1α,25(OH)2D3 or 19-nor-2β-(3-hydroxypropyl)-1α,25(OH)2D3 for 7 days. 19-Nor-2α-(3-hydroxypropyl)-1α,25(OH)2D3 and 19-nor-2β-(3-hydroxypropyl)-1α,25(OH)2D3 were also shown to be about 10-fold more active than 1α,25(OH)2D3 in cell invasion studies using prostate cancer cells. In conclusion, a substitution at the C-2 position of 19-nor-1α,25(OH)2D3 molecule with a hydroxypropyl group greatly increased the antiproliferative and anti-invasion potencies. Thus, these two analogs could be developed to be effective therapeutic agents for treating early and late stages of prostate cancer. 相似文献
10.
A set of eight 1-hydroxyvitamin D3 compounds comprising the four possible (5Z)-1,3-diol stereoisomers and the corresponding (5E)-double bond isomers, has been prepared in order to assess the effect of 1,3-diol stereochemistry and 5,6-double bond geometry on binding affinity for the intestinal 1,25-(OH)2D3-receptor protein. The compounds were synthesized from either vitamin D3 or 3-epivitamin D3 via 3,5-cyclovitamin D intermediates. Competitive receptor binding assays establish that all changes from the natural ring A-configuration (1S, 3R, 5Z) lead to decreased binding affinity, and confirm the importance of the 1-hydroxy function since the conversion of stereochemistry at that center from 1α(S) to 1β(R) has the most pronounced effect on binding affinity (attenuation by more than three orders of magnitude). Other modifications (i.e., conversion at C-3, or cis to trans isomerization of the 5,6-double bond) decrease binding affinity by more moderate (ca. 10-fold) but cumulative factors. 相似文献
11.
Martin Hewison Fiona Burke Katie N. Evans David A. Lammas David M. Sansom Philip Liu Robert L. Modlin John S. Adams 《The Journal of steroid biochemistry and molecular biology》2007,103(3-5):316
Although ectopic expression of 25-hydroxyvitamin D3-1α-hydroxylase (1α-OHase) has been recognized for many years, the precise function of this enzyme outside the kidney remains open to debate. Three specific aspects of extra-renal 1α-OHase have attracted most attention: (i) expression and regulation in non-classical tissues during normal physiology; (ii) effects on the immune system and inflammatory disease; (iii) expression and function in tumors. The most well-recognized manifestation of extra-renal 1α-OHase activity remains that found in some patients with granulomatous diseases where locally synthesized 1α,25(OH)2D3 has the potential to spill-over into the general circulation. However, immunohistochemistry and mRNA analyses suggest that 1α-OHase is also expressed by a variety of normal human tissues including the gastrointestinal tract, skin, vasculature and placenta. This has promoted the idea that autocrine/paracrine synthesis of 1,25(OH)2D3 contributes to normal physiology, particularly in mediating the potent effects of vitamin D on innate (macrophage) and acquired (dendritic cell) immunity. We have assessed the capacity for synthesis of 1,25(OH)2D3 in these cells and the functional significance of autocrine responses to 1α-hydroxylase. Data suggest that local synthesis of 1,25(OH)2D3 may be a preferred mode of response to antigenic challenge in many tissues. 相似文献
12.
Prostaglandin (PG)F2α, E2, D2 and 6-keto-F1α were determined in human cerebrospinal fluid by a mass spectrometric technique. The samples were obtained from 12 patients with suspected intracranial disease. A 64 fold variation in PG levels was observed. The major PG was 6-keto-F1α (0.12–15 ng/ml). PGF2α and PGE2 were present in lower concentrations PGD2 was below the level of detection (0.05 ng/ml) except in one patient with extremely high total levels of PGs. 相似文献
13.
Atsuko Takeuchi Yuki Ishida Hiroko Sekimoto Sonoko Masuda Toshio Okano Soroku Nishiyama Ichiro Matsuda Tadashi Kobayashi 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1997,691(2):1987
A simplified method for the determination of 25-hydroxy and 1α,25-dihydroxy metabolites of vitamins D2 and D3 in human plasma was developed. Plasma samples were deproteinizated and applied to a Bond Elut C18 OH cartridge to separate 25-hydroxyvitamin D (25-OH-D) and 1α-25-dihydroxyvitamin D [1,25(OH)2D] fractions. The 25-OH-D fraction was purified by a Bond Elut C18 cartridge and 25-OH-D2 and 25-OH-D3 were assayed by HPLC using a Zorbax SIL column. The 1,25(OH)2D fraction obtained above was subsequently applied to HPLC using a Zorbax SIL column to separate 1,25(OH)2D2 and 1,25(OH)2D3 fractions which were determined by a radioreceptor assay (RRA) using calf thymus receptor. The method was applied to nutritional studies. 相似文献
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Mei-Ling Siu-Caldera Jeffrey W. Clark Anabela Santos-Moore Sara Peleg Yan Yun Liu Milan R. Uskokovi Surendra Sharma G. Satyanarayana Reddy 《The Journal of steroid biochemistry and molecular biology》1996,59(5-6)
1α,25(OH)2-16-ene-D3, a synthetic analog of the steroid hormone, 1α,25(OH)2D3, has great potential to become a drug in the treatment of leukemia and other proliferative disorders, because of its minimal in vivo calcemic activity associated with a potent inhibitory effect on cell growth. However, at present, the mechanisms through which 1α,25(OH)2-16-ene-D3 expresses its biological activities are still not completely understood. Our previous in vitro study in a perfused rat kidney indicated for the first time that 1α,25(OH)2-16-ene-D3 and 1α,25(OH)2D3 are metabolized differently. 1α,25(OH)2-24-oxo-16-ene-D3, an intermediary metabolite of 1α,25(OH)2-16-ene-D3 formed through the C-24 oxidation pathway, accumulated significantly in the perfusate when compared to 1α,25(OH)2-24-oxo-D3, the corresponding intermediary metabolite of 1α,25(OH)2D3. In a subsequent in vivo study, we also reported that 1α,25(OH)2-24-oxo-16-ene-D3 exerted immunosuppressive activity equal to its parent, without causing significant hypercalcemia. In order to establish further the critical role of 1α,25(OH)2-24-oxo-16-ene-D3, in generating some of the key biological activities ascribed to its parent, we performed the present in vitro study using a human myeloid leukemic cell line (RWLeu-4) as a model. Comparative target tissue metabolism studies indicated that 1α,25(OH)2-16-ene-D3 and 1α,25(OH)2D3 are metabolized differently in RWLeu-4 cells, and the differences were similar to the ones we previously observed in the rat kidney. The significant finding was the accumulation of 1α,25(OH)2-24-oxo-16-ene-D3 in RWLeu-4 cells because of its resistance to further metabolism. Biological activity studies indicated that both 1α,25(OH)2-16-ene-D3 and its 24-oxo metabolite produced growth inhibition and promoted differentiation of RWLeu-4 cells to the same extent, and these activities were several fold higher than those exerted by 1α,25(OH)2D3. In addition, the genomic action of each vitamin D compound was assessed in a rat osteosarcoma cell line (ROS 17/2.8) by measuring its ability to transactivate a gene construct containing the vitamin D response element of the osteocalcin gene linked to the growth hormone reporter gene. In these studies, both 1α,25(OH)2-16-ene-D3 and its 24-oxo metabolite exerted similar but potent transactivation activity which was several fold greater than that exerted by 1α,25(OH)2D3 itself. In summary, our results indicate that the production and slow clearance of the bioactive intermediary metabolite, 1α,25(OH)2-24-oxo-16-ene-D3, in RWLeu-4 cells contributes significantly to the final expression of the enhanced biological activities ascribed to its parent analog, 1α,25(OH)2-16-ene-D3. 相似文献
16.
Gary H. Posner M.Christina White Patrick Dolan Thomas W. Kensler Shigefumi Yukihiro Sandra E. Guggino 《Bioorganic & medicinal chemistry letters》1994,4(24)
Calcitrol analogs 5, designed to combine two remote structural changes each of which separately produces a sharply different biological profile, have biological activities that are a blending of the effects of each structural change. 相似文献
17.
Zhang Xiaoyu Biswas Payal Owraghi Melissa Laura P. Zanello 《The Journal of steroid biochemistry and molecular biology》2007,103(3-5):457
1α,25(OH)2-vitamin D3 (1,25D) is considered a bone anabolic hormone. 1,25D actions leading to bone formation involve gene transactivation, on one hand, and modulation of cytoplasmic signaling, on the other. In both cases, a functional vitamin D receptor (VDR) appears to be required. Here we study 1,25D-stimulated calcium signaling that initiates at the cell membrane and leads to exocytosis of bone materials and increased osteoblast survival. We found that rapid 1,25D-induction of exocytosis couples to cytoplasmic calcium increase in osteoblastic ROS 17/2.8 cells. In addition, we found that elevation of cytoplasmic calcium concentration is involved in 1,25D anti-apoptotic effects via Akt activation in ROS 17/2.8 cells and non-osteoblastic CV-1 cells. In both cases, 1,25D-stimulated elevation of intracellular calcium is due in part to activation of L-type Ca2+ channels. We conclude that 1,25D bone anabolic effects that involve increased intracellular Ca2+ concentration in osteoblasts can be explained at two levels. At the single-cell level, 1,25D promotes Ca2+-dependent exocytotic activities. At the tissue level, 1,25D protects osteoblasts from apoptosis via a Ca2+-dependent Akt pathway. Our studies contribute to the understanding of the molecular basis of bone diseases characterized by decreased bone formation and mineralization. 相似文献
18.
J.D. Wark J.L. Taft V.P. Michelangeli M.C. Veroni R.G. Larkins 《Prostaglandins & other lipid mediators》1984,27(3):453-463
The effect of PGE2 on the conversion of 25-hydroxyvitamin D3 (25 OH D3) to 1,25-dihydroxyvitamin D3 (1,25- (OH) 2D3) by isolated renal tubules from vitamin D deficient chicks was studied under a variety of experimental conditions. In the absence of added vitamin D metabolites, PGE2 (2 × 10−6M) caused an immediate inhibition of formation of 1,25-(OH) 2D3, followed by a delayed stimulation, apparent after 15 h exposure to PGE2. Pretreatment of the tubules with 1,25-(OH) 2D3 prevented the immediate inhibitory action of PGE2, and allowed the stimulation to be apparent after 4 h exposure to PGE2. The cyclic nucleotide phosphodiesterase inhibitor 3-isobutyl-1-methyl xanthine (IBMX) significantly stimulated the formation of 1,25-(OH) 2D3. PGE2 significantly inhibited 1,25-(OH) 2D3 formation in tubules which had been stimulated by IBMX. PGE2 stimulated the adenylate cyclase activity in a crude particulate fraction from the chick kidney, and raised cyclic adenosine 3′, 5′-monophosphate (cyclic AMP) levels in the renal tubules.It is concluded that PGE2 can either stimulate or inhibit 1,25-(OH) 2D3 formation in chick renal tubules. The stimulatory effect may be partly due to elevation of cyclic AMP. The mechanism of the inhibitory effect requires further investigation. 相似文献
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Salvatore V. Pizzo John J. Pasqua 《Biochimica et Biophysica Acta (BBA)/General Subjects》1982,718(2):177-184
The clearance of human fibrinogen fragments D1, D2, D3 and fibrin fragment D1 dimer were studied in the mouse model. Clearance of these fragments is a complex process involving clearance from blood into three other compartments. The overall clearance of fragment D1 and its dimer were essentially identical. Fragments D2 and D3 cleared at a progressively slower rate. Competition studies were performed between 125I-labeled fragment D1 and large molar excesses of unlabelled human fragments D1, D2, D3, D1 dimer, fragment E, fibrinogen, macroalbumin, mannan and asialooroscomucoid. Of these ligands only the fragment D variants competed for the clearance of 125I-labeled fragment D1. Cross-competition was observed when 125I-labeled fragment D1 dimer was cleared in the presence of large molar excesses of fragment D1. Autopsies demonstrated that injected fragments D1, D2, D3 and D1 dimer cleared primarily in liver and kidneys. In some clearance studies, livers were perfused with tissue culture fluid, subjected to light microscopic autoradiography, and silver grain counts performed to localize cleared fragment D1. These experiments indicated that 80% of the liver uptake was in hepatocytes. However, when silver grain counts were normalized for the number of parenchymal and nonparenchymal cells, the distribution of silver grains was essentially identical (1.8 and 1.6 grains per cell, respectively). It is concluded that fragments D1, D2, D3 and D1 dimer are recognized by a similar clearance pathway. Since neither fibrinogen nor fragment E competed for the clearance of fragment D1, it is suggested that determinants present in the fragment D domain become exposed after plasmin attack on fibrinogen and are responsible for clearance. 相似文献