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维生素D除具有调控钙、磷代谢和骨稳态等作用之外,在其他组织中也发挥多种活性作用,如调控免疫系统和调节细胞增殖与分化等方面的新作用。维生素D受体（VDR）除了在其传统组织如骨、肠道和肾脏中发现以外,还在众多组织中被发现。此外,这些组织中亦含有酶CYP2781,其可使维生素D循环形式25-OH—D3转化生成1,25（OH）2D3。1,25（OH）2D3在非肾组织中的代谢与肾脏不同,且VDR介导的转录活性调控作用也是细胞特异性的,因而维生素D的新作用具有细胞特异性,这为维生素D及其类似物提供了许多新的,临床应用依据,但其非传统作用也受到维生素D传统作用的限制,如高血钙和高尿钙。 相似文献
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目的 探讨1,25-(OH)2D3及TLR4配体(脂多糖,LPS)对2型糖尿病(T2DM)和糖尿病肾病(diabetic nephropathy,DN)尿毒症患者血清干预的单核细胞维生素D受体(VDR)表达的影响,进一步探索1,25-( OH)2D3在T2DM和DN炎症性免疫反应中的作用.方法 分离研究对象(健康对照组、T2DM组和DN尿毒症组)外周血血清,孵育THP-1单核细胞,然后于含或不含10-7 mol/L的1,25-(OH)2D3培养液中培养48 h后,再用终浓度为1μg/ml的LPS干预24h,收集单核细胞和培养上清.采用RT-PCR检测VDR mRNA表达,Western blot、免疫荧光检测THP-1单核细胞内VDR蛋白表达.ELISA法检测细胞培养上清IL-6和IL-10浓度.结果 与正常对照组比较,在LPS的刺激下T2DM组和DN尿毒症组THP-1单核细胞内VDR mRNA水平下调[对照组(0.99±0.25);T2DM组(0.65±0.24);DN尿毒症组(0.62±0.27),P＜0.05];DN尿毒症组THP-1单核细胞内VDR蛋白表达比正常对照组和T2DM组显著下调[对照组(0.48 ±0.05);T2DM组(0.50±0.06);DN尿毒症组(0.20±0.01),P＜0.01],且LPS增强以上患者血清孵育的THP-1单核细胞炎症细胞因子IL-6的分泌[对照组(15.13±1.61);T2DM组(24.06 ±2.92);DN尿毒症组(70.77 ±5.48),P＜0.05];而1,25-(OH)2D3可部分阻断上述作用.结论 LPS能下调T2DM和DN尿毒症患者单核细胞VDR mRNA和蛋白的表达,引起促炎和抗炎细胞因子失调.1,25-(OH)2D3可部分逆转LPS的作用,对T2DM和DN尿毒症可能具有一定的保护作用. 相似文献
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维生素D的应用形式有维生素D2、D3、25-OHD3和1,25-(OH)2-D3几种形式,其中D3为最常用的形式。25-OH-D3是维生素D 3在肝脏中转化后的一种形式,随后又在肾脏中转化为最终活性形式1,25-(OH)2-D3。作为维生素D3和1,25-(OH)2-D 3的中间产物,25-OH-D3在动物体内活性比维生素D3更高,吸收更有效。1维生素D的生理功能及其在动物体内的代谢维生素D通过类似于类固醇激素的作用机理对动物的许多生物学功能进行调节,主要在以下几个方面发挥作用:1)维持动物体内钙、磷稳恒,保持骨骼的正常生长发育,防止钙缺乏症,如软骨病、佝偻病等,这是维生素D最重要的生理功能。2)提高肉品质。维生素D可刺激机体骨钙的动员,并且促进扩流入骨骼肌细胞中,使钙激酶被激活,从而促进肉的嫩化。 相似文献
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维生素D(VD)与骨代谢的钙磷吸收有着非常密切的关系,其体内活性形式为1,25 (OH)2D3。而VD受体（VDR）是介导1,25 (OH)2D3发挥生物效应的核内生物大分子。近年来,随着对骨病研究的深入,对VDR基因与骨代谢关系的研究越来越受到国内外学者的重视。在不同群体甚至不同个体中,VDR基因极容易表现出多态性。目前大量的研究集中在VDR基因4个单核苷酸多态性（single nucleotide polymorphism,SNP）位点FokI、BsmI、ApaI、TaqI与骨代谢之间的关系。作者分别从钙吸收、骨量、骨密度、骨质疏松、佝偻病等方面对VDR基因与骨代谢关系进行综述。 相似文献
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关于维生素D生物学效价的评定方法主要分为生物学方法和化学方法,然而至今对其没有统一的结论。研究结果大部分显示维生素D3的效价高于或等于维生素D2的效价,且维生素D3及其代谢产物效价的对比大致为维生素D3≤24,25-二羟基维生素D3[24,25-(OH)2D3]=25,26-二羟基维生素D3[25,26-(OH)2D3]≤25-羟基维生素D3[25-(OH)D3]≤1,25-二羟基维生素D3[1,25-(OH)2D3]。影响维生素D生物学效价的因素有多种,其内在因素主要包括关键酶的活性及其反馈调节机制、活性维生素D的结构与维生素D转运蛋白及维生素D受体的亲和性差异等;外在因素主要有试验动物、评价指标及评价方法、光照、维生素D载体等。本文主要从维生素D生物学效价的评定方法、内在和外在的影响因素方面进行综述,为相关研究提供一定的参考依据。 相似文献
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旨在研究1,25(OH)2D3是否通过VDR途径调节山羊附睾头上皮细胞β防御素基因表达。本试验选取3只6月龄太行黑山羊，分别采集附睾头组织。采用差速贴壁法分离山羊附睾头上皮细胞，用细胞免疫荧光鉴定上皮细胞纯度。添加100 nmol·L-1 1,25(OH)2D3处理附睾头上皮细胞以及筛选出敲除效率最高的pCas9/gRNA1质粒载体进行细胞转染，同时设置阴性对照组和空白对照组，每组3个重复孔。附睾头上皮细胞经1,25(OH)2D3处理以及VDR基因敲除后，分别用qRT-PCR检测VDR和17种β防御素基因的表达，用Western blot检测VDR蛋白和3种β防御素蛋白的表达。结果表明，1,25(OH)2D3能极显著提高VDR、gBD124、gBD126和gBD104a的mRNA和蛋白表达(P<0.01),同时极显著提高gBD104、gBD109tr1、gBD109tr2、gBD113... 相似文献
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饮水添加25-OH-D3对肉仔鸡胫骨质量的影响 总被引：1，自引：0，他引：1
维生素D是促进动物机体钙磷吸收的主要因素，对动物骨骼生长有重要意义；而动物从日粮中摄取的维生素D必须转化为25-OH-D3、1,25-（OH）2-D3、25，26-（OH）2-D3等代谢物后才具有生物活性，并有效地发挥其生理生化功能。 相似文献
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《中国兽医学报》2020,(10)
旨在探明1,25(OH)_2D3对猪伪狂犬病病毒(pseudorabies virus,PRV)诱导小鼠流产的影响。采用颈背部皮下注射不同剂量PRV建立PRV诱导小鼠流产模型;通过实时荧光定量PCR检测不同剂量1,25(OH)_2D3预处理组和生理盐水预处理组小鼠卵巢和子宫内VDR mRNA的水平及PRV量;利用组织学病理切片技术观察PRV引起的1,25(OH)_2D3预处理组和生理盐水处理组小鼠子宫和卵巢的病理变化。结果显示,成功建立了小鼠流产模型,确定了引起小鼠流产的PRV最佳接种剂量为0.35 mL 1 000 TCID_(50) PRV;用300μg/kg 1,25(OH)_2D3预处理,小鼠VDR表达水平最高,能有效抑制病毒的增殖,对PRV感染小鼠流产的抑制作用最强。组织病理学检查发现,相较于生理盐水预处理的PRV感染组,1,25(OH)_2D3预处理组小鼠卵泡腔内颗粒细胞增多、红细胞量减少;子宫腔内红细胞数量减少或消失,子宫内膜皱褶增多。结果表明,1,25(OH)_2D3能有效抑制PRV增殖,降低PRV诱导的小鼠流产。 相似文献
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据报道,向低钙高磷肉鸡日粮中添加10μg/kgl,25—二羟维生素D_3[1,25-(OH)_2D_3]可以降低其胫软骨发育不良(TD)的发生率并增加骨灰分含量。但有时可引起饲料转化率降低。一些研究报告,5μg/kgl,25-(OH)_2D_3就可有效降低肉鸡的TD。但是,这些研究都是用电热笼架式育雏器进行试验的。在商品生产中,降低舍饲肉鸡TD发生率所需要的1,25-(OH)_2D_3含量尚无评价。 最近,美国佐治亚州立大学的Kevin D.Roberson等人通过试验研究评价了在实际条件下饲养肉鸡3和5周龄时降低TD发生率所需日粮1,25-(OH)_2D_3的含量。 试验用日龄Peterson×Arbo Acres肉鸡小公鸡进行,饲养于有刨花垫料的平养鸡栏中,用白炽灯连续光照,自由采食和饮水,试验期5周。基础日粮为可以引起TD的低钙高磷日粮。试验日粮添加3、6或9μg/kgl,25 相似文献
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<正>维生素D通过调节钙、磷吸收维持动物机体正常功能。养殖生产中,通常采用维生素D3来满足畜禽维生素D的需要。维生素D3吸收入机体后,首先在肝脏中转化成25-羟基钙化醇(25-OH-D3)然后到达肾脏被羟化成激素形式的代谢物1,25-(OH)2-D3实现维生素D的生物学功能。研究认为Hy.D(25-OH-D3)不受肠道胆酸分泌和脂肪的影响,比维生素D3更易吸收;而且可避免维 相似文献
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VD在骨骼外系统中的作用及其研究进展 《畜牧与饲料科学》2021,42(3):43-46
以往普遍认为VD的主要功能是调节Ca离子来促进骨骼的生长和预防佝偻病,但最近几年的研究发现,VD不仅在骨骼疾病中起到重要作用,还与多种骨骼外疾病密切相关,包括一些心血管疾病、代谢紊乱有关的疾病、恶性肿瘤、过敏性疾病、自身免疫性疾病、生殖方面影响等。目前对VD生物学功能的研究比较全面和深入,但大部分是针对人体和小鼠的基础研究,对诸如牛、猪、犬、猫等不同动物VD的骨骼外系统生物学功能的研究较少。在查阅相关文献的基础上,通过对VD在血压、免疫调节、内分泌、子宫内膜和骨骼肌方面的生物学功能和研究进展进行总结,为不同动物VD在骨骼外系统生物学功能的研究提供一定参考。 相似文献
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Recently, the type II sodium-dependent phosphate cotransporter NaPi IIb, which mediates the intestinal phosphate transport, was detected in the apical membranes of caprine mammary gland epithelial cells. Regulatory influences of developmental stages, dietary phosphorus (P) supply and hormones like calcitriol are well described for the intestinal NaPi IIb. Therefore, it was the aim of this study to examine the influence of involution and dietary P restriction on the expression of mammary gland NaPi IIb and of vitamin D receptor (VDR). During involution both, NaPi IIb and VDR, showed an initial increase of expression. This resulted in a delayed response on protein level. Dietary P restriction resulted in a decrease of mRNA expression which was not reflected on protein level. Influenced expression pattern, at least on mRNA level, indicate that mammary gland NaPi IIb is a regulated phosphate transporter which might have an important role especially during involution. Coexpression pattern with VDR provides an indication that calcitriol could be the modulator of these adaptive responses to involution and dietary P restriction. Therefore, a physiological meaning of NaPi IIb in mammary gland epithelia during processes of cell regeneration has to be considered. 相似文献
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为了探索维生素D受体(VDR)在SD大鼠脂肪细胞分化过程中的表达规律,采用Ⅱ型胶原酶消化法进行SD大鼠脂肪细胞的分离培养,并将其诱导分化为成熟的脂肪细胞,分别在细胞生长至单层汇合后的第0、4、8、12、16天收集细胞样品。对VDR和脂滴进行荧光染色,同时采用Western blot对脂肪细胞分化过程中的VDR蛋白表达量进行分析,采用real-time PCR定量分析脂肪细胞分化过程中的VDR表达量。结果显示,随SD大鼠脂肪细胞的分化,细胞中脂滴逐渐增加,VDR mRNA和蛋白的表达量与脂质积累过程呈负相关性,表明VDR的表达在脂肪细胞分化过程中有一定的变化规律,其可能以负反馈的调节机制参与了脂肪细胞的分化过程。 相似文献
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D. Haxhiu S. Hoby C. Wenker A. Boos M. P. Kowalewski F. Lewis A. Liesegang 《Journal of animal physiology and animal nutrition》2014,98(6):1021-1030
The purpose of this study was to investigate the influence of feeding and UVB exposition on the occurrence and distribution patterns of vitamin D receptors (VDR) and calbindin D28k (Cb‐D28k) in the gastrointestinal tract of veiled chameleons. Thus, 56 veiled chameleon hatchlings were divided into six treatment groups: UV (with UVB exposure); No (no supplements, no UVB exposure); CaAUV (with calcium (Ca), vitamin A supplementation, UVB exposure); CaA (with Ca, vitamin A supplementation); CaADUV (with Ca, vitamin A, vitamin D supplementation, UVB exposure); and CaAD (with Ca, vitamin A, vitamin D supplementation). Animals were reared under the suspected conditions for 6 months on locust‐based diets. Tissue samples of stomach, duodenum, ileum and colon were taken, and semi‐quantitative immunohistochemical methods (IHC) were performed to detect Cb‐D28k and VDR. VDR immunoreactions were higher in the luminal epithelium of the duodenum than in that of the ileum. VDR immunoreactions in the luminal epithelium were higher at the base of the villi of the duodenum as compared to the tip. Cb‐D28k immunoreactions were mainly observed in the luminal epithelium of the duodenum. The two groups treated with all dietary supplements (CaADUV, CaAD) exhibited a higher Cb‐D28k immunoreaction as those with no supplements and UVB exposure only. No immunoreaction for both proteins could be detected in the stomach. This study suggests that the duodenum plays an important role in the active transcellular absorption of Ca in veiled chameleons as shown by the immunohistochemical detection of VDR and Cb‐D28k. Expression of Cb‐D28k, in particular, appears to be regulated by dietary supplementation of vitamin D and vitamin A. VDRs, however, tended to be upregulated when animals were not supplemented with Ca, vitamin D and vitamin A. This may be due to the decreased Ca concentrations which caused vitamin D activation in the skin without any supplementation, but UVB exposure. 相似文献
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Two experiments were conducted to investigate the effects of 1,25(OH)2D3 to stimulate Na+-dependent phosphate uptake in Caco-2 cells, and the effects of dietary vitamin D supplementation to vitamin D-deficient nursery pigs on Na+-dependent nutrient uptake and mRNA expression of NaPi-IIb cotransporter and calbindin D9k in the jejunum. In Exp. 1, 250,000 Caco-2 cells were seeded on Costar 12 mm Snapwell inserts with a 0.40 µm polycarbonate filter and a seeding density of 0.25 × 106 and studied at 15 d postconfluence. Cells were treated with 10 nM of either 1,25(OH)2D3 or vehicle for 48 h and then mounted in modified Ussing chambers for transepithelial measurements. In Exp. 2, pigs (n = 32) were removed from sows at 3 d of age, placed on a vitamin D-deficient milk replacer diet and housed in a room devoid of sunlight and UV light in the range of 280 to 300 nm. On day 28, serum 25(OH)D3 concentrations were measured to verify low vitamin D status. Pigs (BW 10.10 ± 0.38 kg) were then individually housed day 28 postweaning and allotted to 1 of 2 dietary treatments. Dietary treatments consisted of corn-soybean-based diets with vitamin D supplementations of 0 or 1,500 IU/kg diet for 12 d. Blood samples were taken from the brachiocephalic vein on the initial (day 0) and final day (day 10, 11, or 12) of the study for analysis of serum 25(OH)D3, P, and Ca. Pigs were euthanized and jejunal segments were harvested and used in modified Ussing chambers and for RNA isolation and subsequent quantitative RT-PCR analysis. In Exp. 1, treating Caco-2 cells with 10 nM 1,25(OH)2D3 resulted in a 52% increase (P < 0.005) in Na+-dependent phosphate uptake compared with cells treated with a vehicle. In Exp. 2, Na+-dependent phosphate and glucose transport did not differ (P > 0.10) among treatment groups. Additionally, NaPi-IIb and calbindin D9k mRNA expression were not different (P > 0.10) between treatment groups. No differences (P > 0.10) were detected in final serum P or 25(OH)D3 concentrations between treatments. However, serum Ca linearly increased (P < 0.05) as the concentration of supplemental vitamin D increased in the diet. Overall, while 1,25(OH)2D3 stimulated Na+-dependent phosphate uptake in Caco-2 cells, supplementing diets with 1,500 IU/kg vitamin D3 from cholecalciferol did not increase jejunal Na+-dependent phosphate uptake or NaPi-IIb mRNA expression over that of pigs fed diets with no supplemental cholecalciferol. 相似文献