骨代谢相关血液生化指标的研究进展

骨代谢包括骨合成和骨吸收两个过程。受到很多因素的影响,遗传、营养、环境、性别及内分泌等都是关键调节因素。当骨吸收过程大于骨合成过程,导致骨量流失,骨密度降低,进一步发展为骨质疏松症。骨代谢过程受到内分泌的影响,很多骨代谢血液生化指标对骨病的研究起到重要作用。近年来,国内外大量的研究报道了与骨代谢相关的血液生化指标。作者着重对血钙与血磷、甲状旁腺激素、1,25-二羟维生素D₃、白细胞介素、血清总碱磷酶和骨碱磷酶等骨代谢血液生化指标对骨形成和分解的影响进行了综述。     

低磷酸盐血症与骨组织代谢调节因子

当发生低磷酸盐血症时都伴有骨质疏松，而骨形成、骨吸收和钙代谢过程主要受甲状旁腺激素（PTH）、维生素D及其活性代谢产物１，２５－（OH）２－D３和骨钙素、降钙素等钙调激素的调节，骨形成及骨吸收保持着相对平衡，血液中的激素处于平衡状态，这一平衡状态受到破坏或内分泌发生紊乱时，就会引起代谢性骨病，因此这些激素对于诊断和全面认识低磷酸盐血症有重要的理论意议。１甲状旁腺素甲状旁腺分泌的甲状旁腺素对其靶器官—骨组织的作用复杂多样，是调节骨代谢的重要激素之一。该激素主要作用于骨组织，使间充质细胞向破骨细胞（OC…     

成纤维细胞生长因子23在骨矿物质代谢中的作用及其调控机理

骨源性激素成纤维细胞生长因子23(FGF23)介导由甲状旁腺、肾脏、骨骼和维生素D组成的负反馈回路,建立"骨骼-肾脏-甲状旁腺"内分泌轴,参与骨矿物质代谢并发挥重要作用。钙、磷、铁、维生素D、甲状旁腺素(PTH)、成纤维细胞生长因子受体(FGFR)/FGF以及蛋白质翻译后修饰调控FGF23的分泌、活性和胞内过程。随着深入的研究,探索出了一些以FGF23为靶点治疗骨矿物质代谢障碍疾病的新疗法。本文综述了FGF23在骨矿物质代谢中的作用及其调控机理的研究进展,以期为相关研究提供参考依据。     

OPG/RANKL/RANK系统的生理功能

骨是一个代谢活跃的器官,在整个生命周期中都在进行不断的更新与重建。在骨形态发生和重建的过程中主要受到细胞因子和激素的调节,同时骨代谢也受到OPG/RANKL/RANK系统的调控。论文主要对骨骼生理结构与骨组织细胞之间的关系,骨代谢和骨的形成过程,OPG/RANKL/RANK系统的生理功能,OPG/RANKL/RANK系统的影响因子以及骨代谢紊乱所引起的疾病几个方面作一综述。     

PTHrP-Ihh信号轴对软骨内成骨的调控作用

长骨的生长主要经过软骨内成骨和膜内成骨。软骨内成骨即长骨干骺端生长板的发育过程,生长板软骨细胞从静止期到增殖期再到肥大期及钙化期的排列、增殖、分化、矿化、血管化等一系列过程调节着长骨的生长。生长板软骨细胞的分化和成熟的过程受全身或者局部多种激素,细胞因子的调控。其中印第安刺猬蛋白(Indian hedgehog,Ihh)与甲状旁腺激素相关肽(Parathyroid hormone-related peptide,PTHrP)所形成的信号系统在骨骼生长板中软骨细胞的增殖、分化、肥大、凋亡及软骨基质钙化过程中,具有重要的调控作用。     

OPG/RANKL/RANK系统的生理功能

 骨是一个代谢活跃的器官,在整个生命周期中都在进行不断的更新与重建。在骨形态发生和重建的过程中主要受到细胞因子和激素的调节,同时骨代谢也受到OPG/RANKL/RANK系统的调控。论文主要对骨骼生理结构与骨组织细胞之间的关系,骨代谢和骨的形成过程,OPG/RANKL/RANK系统的生理功能,OPG/RANKL/RANK系统的影响因子以及骨代谢紊乱所引起的疾病几个方面作一综述。     

钙磷代谢对动物骨骼健康影响的研究进展

骨骼构成机体结构的基本框架,骨形成和骨吸收的动态平衡关系到骨骼健康。钙和磷是动物体骨骼生长发育过程中重要的矿物质元素,机体对其吸收与调控直接影响骨代谢过程。血钙和血磷水平的变化,改变了机体相关调节激素的分泌,而这些激素可影响骨骼发育,因此,钙、磷代谢与骨骼健康紧密相关。综合国内外钙、磷代谢和骨代谢等方面的研究,从钙、磷的吸收和代谢,含量和比例以及钙磷代谢相关调节激素对骨骼发育的调控机制等方面进行综述,旨在为后续动物钙、磷代谢和骨骼之间调控的研究提供参考。     

骨形态发生蛋白与骨代谢

骨形态发生蛋白（bone morphogenetic protein,BMPs）是乙型转化生长因子（TGF-β）超家族的成员之一,BMPs能诱导促进软骨和骨的形成,对造骨细胞、造骨基因和造骨功能均具有调节作用。BMPs同其细胞微环境中的激素和局部信号一起决定骨髓间充质干细胞的分化方向,对BMPs调节的基因及调节BMPs的基因的进一步研究,将会为探讨人和动物骨代谢疾病的发生机制及相关治疗带来新的方向。     

矿物元素钙在奶牛生产中的应用

<正>调节和控制体内钙代谢的重要物质为甲状旁腺激素(PTH),降钙素(CT)和维生素D的活性形式—1、25-(OH)2D3。1奶牛体内钙的代谢过程1.1钙在骨骼中的代谢钙在骨骼中有两种存在方式,绝大多数以CaHPO4的形式紧密结合在骨胶原蛋白基质上,一小部分以离子形式存在于骨细胞外液和骨胞内小     

大围山微型鸡骨代谢生化指标与骨密度研究

骨骼发育处于骨代谢的动态平衡过程中,且骨代谢与骨密度紧密相连。为研究家禽骨代谢生化指标与骨密度的相关性,本研究以大围山微型鸡为研究对象,以艾维茵肉鸡作对照,检测骨代谢血液生化指标含量与骨密度。结果显示,在0~150日龄生长期,大围山微型鸡血钙、血磷、碱性磷酸酶含量和骨密度均高于艾维茵肉鸡,而甲状旁腺素含量则相反;相关性研究显示,血钙、血磷、碱性磷酸酶含量与骨密度呈正相关,而甲状旁腺素含量与骨密度呈负相关。研究表明选育或驯化可能是导致不同品种家鸡骨代谢及骨密度差异的重要原因。     

轻度缺钙对笼养蛋鸡内分泌及骨代谢的影响

选用58周龄新扬州鸡产蛋母鸡300只,随机设计分为2组(对照组、低钙组),每组5个重复,分别饲喂钙水平为3.5%、2.5%的玉米-豆粕型日粮,研究轻度缺钙对老龄蛋鸡骨钙素(BGP)、甲状旁腺素(PTH)、降钙素(CT)、雌二醇(E2)及骨密度(BMD)的影响。结果表明,轻度钙供应不足情况下,骨质疏松逐渐明显,BGP升高,E2、BMD均下降,BGP、E2、BMD变化显著。PTH、CT均呈升高趋势,但变化不显著。结论:轻度缺钙时,老龄蛋鸡骨代谢和雌激素发生了显著变化,但对钙调节激素的影响不显著。     

Disorders of the parathyroid glands

The three calcitropic hormones, parathyroid hormone (PTH), 1,25-dihydroxycholecalciferol and calcitonin are together responsible for calcium homeostasis in the mammal. Feline PTH is an 84 amino acid, single chain polypeptide with a molecular weight of 9449, which is secreted by the parathyroid glands. The principle secretagogue for PTH is a low plasma ionised calcium concentration, although both 1,25-dihydroxycholecalciferol and phosphate have significant roles in regulating PTH secretion. The ability to accurately measure circulating PTH in the cat has simplified the evaluation of disorders of calcium metabolism in this species. In primary parathyroid disorders the lesion is located within the parathyroid gland, with parathyroid secretion being inappropriate to the prevailing mineral balance. By contrast, in secondary conditions a pathological state out with the parathyroid gland alters mineral homeostasis and the parathyroid gland responds in an appropriate manner. The measurement of circulating PTH may then be used to determine if PTH secretion is appropriate to the prevailing calcium concentrations to differentiate primary from secondary disorders. Although primary hyper and hypoparathyroidism are generally considered rare endocrine conditions of the cat, the ability to measure PTH has led to their increasing recognition.     

Dietary phosphorus restriction affects bone metabolism,vitamin D metabolism and rumen fermentation traits in sheep

Homeostasis of calcium (Ca) and phosphate (P_i) is maintained by a concerted interplay of absorption and reabsorption via the gastrointestinal tract and the kidney and by storage and mobilization from the bone regulated mainly by parathyroid hormone (PTH), 1,25-dihydroxycholecalciferol and calcitonin. The present study aimed at characterizing the effects of dietary P restriction on bone, vitamin D metabolism and rumen fermentation traits reflecting the endogenous P cycle maintaining the ruminal P supply for microbial metabolism. The experiments were done in eleven female, non-pregnant, non-lactating four- to nine-year-old Black Headed Mutton sheep allotted to two feeding groups: "P-restricted" (0.11% P/kg DM and 0.88% Ca/kg DM) and "Control" (0.38% P/kg DM and 0.88% Ca/kg DM). Dietary P restriction did not lead to hypophosphataemia, probably due to a compensation by bone mobilization, demonstrated by increased serum concentrations of a resorption marker and altered gene expression in bone tissue. In addition, the RNA expression of fibroblast growth factor 23, a bone-derived factor involved in the regulation of vitamin D metabolism, was significantly reduced with dietary P restriction. Furthermore, several genes related to vitamin D metabolism and plasma concentrations of 1,25-(OH)₂D were associated with serum concentrations of phosphate (P_i). In the parotid gland, the expression of the P_i transporter NaPi2b was negatively associated with serum P_i and positively with parathyroid PTH expression. Although P_i concentrations in saliva and the gastrointestinal tract were significantly reduced, we found no adverse effects of the P-restricted ration on the production of short chain fatty acids, but slight differences in the production of butyrate as well as its relationship to rumen P_i and ammonia concentrations that might indicate an impact on ruminal fermentation.     

Some acute metabolic effects of parathyroid hormone in sheep

PERSSON, J. and J. LUTHMAN: Some acute metabolic effects of parathyroid hormone in sheep. Acta vet. scand. 1974, 15, 381–397. — It is now well established that calcium ions play a key role in the activation of many different cell systems. Parathyroid hormone (PTH) causes a shift of calcium into bone cells, and lipolytic hormones have little or no effect in calcium-free media. In the present investigation sheep were used to study the acute effects of intravenous injection of bovine PTH on mineral and lipid metabolism. A significant initial hypocalcaemia was found in all groups of animals. The subsequent rise in plasma calcium was most pronounced in rams. Thyroid-ectomized animals showed a greater calcium response than did intacts. PTH was found to have a strong lipolytic effect, comparable to that of catecholamines, and a slight hyperglycaemic effect. The rise in plasma NEFA was blocked by nicotinic acid, while the hyper-glycaemia was potentiated. Hypophosphataemia was obtained in young rams but not in young ewes, and in elder ewes a slight increase in the plasma phosphate level was found. Plasma magnesium decreased in all groups after PTH injection, while PTH + nicotinic acid caused a rise in magnesium concentration. The results are discussed in the view of current knowledge of mineral and lipid metabolism.parathyroid hormone; hypocalcaemia; lipolysis; sheep.     

Use of a parathyroid hormone peptide (PTH(1-34))-enriched fibrin hydrogel for the treatment of a subchondral cystic lesion in the proximal interphalangeal joint of a warmblood filly

To describe the treatment of a subchondral bone cyst in the proximal phalanx with parathyroid hormone peptide-enriched fibrin hydrogel in a warmblood filly. The cyst was localized with computer-assisted orthopaedic surgery, then curetted and finally filled with parathyroid hormone fragment peptide 1-34 (PTH(1-34)) covalently attached to a fibrin hydrogel. The cyst healed quickly without any complications. This result supports the hypothesis that PTH(1-34) delivered locally in a fibrin hydrogel may improve the postoperative prognosis of surgical management of subchondral bone cysts in horses. Subchondral bone cysts are fairly common in horses. Especially in older horses, the prognosis is poor, even after surgical curettage. Therefore, different management protocols have been investigated in conjunction with surgical curettage to improve prognosis. Locally delivered PTH(1-34) seems to be a new method in the treatment of subchondral bone cysts.     

Parathyroid hormone (1-34) improves bone mineral density and glucose metabolism in Spontaneously Diabetic Torii-Lepr(fa) rats

The Spontaneously Diabetic Torii-Lepr(fa) (SDT-fa/fa) rat, a model of obese type 2 diabetes, shows obesity, hyperglycaemia and low bone mineral density (BMD). The objective of this study is to evaluate the effects of parathyroid hormone (1-34) [PTH(1-34)] on BMD and glucose metabolism in the SDT-fa/fa rat. SDT-fa/fa rats showed obesity with hyperglycaemia and decreased serum osteocalcin levels and the tibial BMD. A 4-week treatment of PTH(1-34) (20 μg/kg/day) increased the serum osteocalcin levels and the tibial BMD, and decreased the serum glucose levels without changing the serum insulin levels. These findings indicate that PTH(1-34) improved not only BMD but also glucose metabolism in SDT-fa/fa rats. This study suggests that PTH(1-34) is a novel agent for the treatment of diabetic osteoporosis.     

Effects of orchidectomy on bone metabolism in beagle dogs

The effects of orchidectomy on bone metabolism in male beagle dogs were examined using twelve 2-year-old dogs that were orchidectomized. The dogs' bilateral iliac bones, double-labeled with tetracycline and calcein for the histomorphometry, were obtained from three dogs prior to orchidectomy and at 3, 6, 9, and 12 months afterwards. The serum biochemical constituents related to bone metabolism were examined before and every month after orchidectomy. Between 1 and 6 months after orchidectomy, the value of serum testosterone decreased (1 month), while the levels of parathyroid hormone, calcitonin, total calcium, osteocalcin, and alkaline phosphatase activity increased significantly, indicating a high bone turnover. The mean trabecular thickness and the fraction of labeled osteoid surface decreased significantly 3 months after orchidectomy, but other histomorphometric parameters were unchanged. In the period 7-12 months after orchidectomy, the parathyroid hormone level increased ever and above that of the first 6-month period, while the levels of calcitonin, osteocalcin, alkaline phosphatase activity, and phosphorus decreased. The bone volume, mean trabecular thickness, and the fraction of labeled trabecular surface decreased significantly compared with the pre-orchidectomy values. These findings indicate an imbalance in bone metabolism (i.e. bone resorption > bone formation). These results indicate that a loss of bone volume accompanied the fall in sex hormone levels following orchidectomy and suggest that the orchidectomized dog is available as an animal model for studying osteoporosis caused by hypogonadism and the decline of sex functions in men.     

Serum parathyroid hormone and calcitonin levels in racehorses with fracture

Serum parathyroid hormone (PTH) and calcitonin (CT) levels in fractured racehorses were measured by radioimmunoassay. Racehorses with fracture of large bone such as the radius, third metacarpus, third carpus, digital bone or tibia, showed normal PTH level and elevated CT level in the serum. Serum PTH level was slightly higher in racehorses with sesamoid bone fracture compared to that of healthy racehorses, but not statistically significant. Moreover, serum CT level of racehorses with sesamoid bone fracture was significantly higher than that of healthy racehorses. Racehorses with sesamoid bone fracture and large bone fracture might be in different conditions of calcium regulation.