氟对骨组织代谢调节因子的影响

过量氟不仅对骨细胞具有直接作用，而且可通过骨代谢调节因子（甲状旁腺素、骨钙素、降钙素）的间接作用，引起骨损害。因此，认识骨代谢调节因子，对深入探讨氟病具有重要的理论意义。     

利用烟草表达一种新型鲑鱼降钙素的初步研究

利用烟草表达一种新型鲑鱼降钙素,以期为利用植物系统表达鲑鱼降钙素的研究提供理论参考。首先构建含外源基因“p il-m sCT”的植物双元表达载体p35S-2300-tw in T-DNA s∶p il-m sCT∶NO S-ter,然后通过农杆菌介导法转化烟草,获得卡那霉素抗性烟草128株,其中PCR阳性植株14株(阳性率10.94%);Sou thern b lotting分析表明外源基因已整合到烟草基因组中,拷贝数为2~8个;半定量RT-PCR结果显示,转基因烟草株间“p il-m sCT”转录水平存在较大差异。     

低氧条件下甘肃鼢鼠鼻黏膜内含SP及CGRP的免疫反应纤维长度变化

运用免疫组织化学方法对比了常氧条件下与低氧条件下甘肃鼢鼠鼻黏膜内含P物质(SP)及降钙素基因相关肽(CGRP)的神经纤维平均长度的变化情况。结果表明,甘肃鼢鼠在低氧条件下,鼻腔嗅黏膜内含SP及CGRP的免疫反应纤维的平均长度与常氧条件下的比率分别为0.97和1.09,呼吸黏膜的比率分别为1.20和1.22,明显小于SD大鼠的相应比率,但差异均未达极显著水平(0.01相似文献   

Immunohistochemical analysis of pseudorabies virus spread through neurons innervating the eyeball

Pseudorabies virus (PRV) was inoculated intraocularly into BALB/c mice, and the distribution pattern of cells positive for several neurotransmitters and viral antigens in the eyeball, trigeminal nerve ganglia, and superior cervical ganglia was examined immunohistochemically to clarify the neural route of the virus spread. In the eyeball, substance P (SP)- and calcitonin gene-related peptide (CGRP)-positive cells were detected in the ipsilateral iris and ciliary body, neuropeptide tyrosine (NPY)-positive cells were detected in the choloid membrane, and tyrosine hydroxylase (TH)-positive cells were detected in the ipsilateral inner nuclear layer of the retina; all these cells contained viral antigens. In the superior cervical ganglia, viral antigen-positive cells containing TH or NPY were found at bilateral sites. In the trigeminal nerve ganglia, viral antigen-positive cells containing SP or CGRP were found at bilateral sites. These findings indicated that the SP- and CGRP-positive ganglion cells of the trigeminal nerve ganglia innervating the iris or ciliary body, and the NPY-positive ganglion cells of the superior cervical ganglia innervating the iris, ciliary body, and choroid membrane served as the route for the virus spread. These findings also suggested that dopaminergic neurons, such as the TH-positive retinal cells and TH-positive ganglion cells of the superior cervical ganglia, served as the route for virus spread.     

ORIGINAL ARTICLE: The approach to the mechanism of calcitonin gene‐related peptide‐inducing inhibition of food intake

The aim of this study was to investigate the anorectic mechanism of calcitonin gene‐related peptide (CGRP) in rats. Intraperitoneal injection of CGRP (50 μg/kg) resulted in decline (p < 0.05) in the food intake of rats at 0.5, 1, 2 and 4 h in comparison with saline control. Compared with saline‐treated group, the levels of hypothalamic 3′,5′‐cyclic adenosine monophosphate (cAMP) and plasma glucagon were increased (p < 0.05) in CGRP‐treated group, but insulin level was decreased (p < 0.05). No significant changes (p > 0.05) in the plasma leptin were observed between two treatment groups. Calcitonin gene‐related peptide injection down regulated (p < 0.05) both neuropeptide Y (NPY) and melanin‐concentrating hormone (MCH) genes at mRNA levels, but up regulated (p < 0.05) the expression of cholecystokinin (CCK) gene. The correlations analysis showed that food intake was negatively correlated (p < 0.05) with CCK mRNA, cAMP and glucagon levels. Moreover, there existed negative correlations (p < 0.05) between MCH mRNA and glucagon levels, and positive correlations (p < 0.05) between insulin and leptin levels. The results showed that cAMP acting as the second messenger may play a vital role in the anorectic effects of CGRP. Calcitonin gene‐related peptide could stimulate anorexigenic neuropeptides (i.e. CCK) and/or inhibit orexigenic neuropeptides (i.e. NPY and MCH) expression, and ultimately suppressed food intake that was functionally coupled to cAMP/PKA pathway activation.     

Evaluation of a Radioimmunoassay Technique Measuring Calcitonin in The Bovine,Ovine and Porcine Species

A heterologous RIA system was set up for measuring bovine, ovine and porcine calcitonin (CT). The system consisted of porcine GT used as standard and for the preparation of an iodinated tracer. The antiserum used was raised against ovine GT. For each analysis was used 25–200 µl blood plasma. Practical detection limit was 0.25 µg of CT per litre of blood plasma.The parallelism between the dose response curves for the p-GT standard and for the assay of increasing amounts of bovine, ovine and porcine blood plasma showed the suitability of the present assay system to study the GT secretion in these species. Furthermore, the reliability of the method was verified by a clearly recognized CT response to calcium infusion.     

P2X2阳性感觉神经末梢在小鼠食管的分布

本文采用免疫荧光组织化学双标方法结合激光共聚焦显微镜技术研究了伤害性受体P2X2阳性感觉纤维末梢在小鼠食管内的分布及与降钙素基因相关肽（CGRP）阳性纤维的关系。结果表明：在食管各水平均可见到P2X2阳性感觉纤维末梢。P2X2阳性纤维集中分布于食管的内、外肌层之间，部分或全部的覆盖在肌间神经节的表面。一些串珠样的纤维深入到肌间神经节内，相互缠绕在一起形成许多结构复杂、形状各异的神经节内板状末稍（IGLEs）。荧光双标显示许多CGRP阳性纤维围绕在P2X2阳性IGLEs周围，没有见到P2X2和CGRP在同一纤维的共存。结状神经节内可见许多中小型神经元表达P2X2，P2X2/CGRP双标神经元稀少，而背根神经节内可见较多的P2X2阳性细胞含有CGRP。由此可见，小鼠食管内部分感觉神经末梢表达伤害性受体P2X2，并形成IGLEs样末梢结构。     

Localization of calcium regulatory hormones in fish

Immunocytochemical localization of hypocalcin, a hypocalcemic factor in the corpuscles of Stannius (CS), in American eels was examined at the light (ABC method) and electron microscopic (protein A-gold technique) levels with the specific antiserum raised against purified rainbow trout hypocalcin. Only type 1 cells in the CS were immunoreactive in the light microscopic immunocytochemistry. At the electron microscopic level, however, hypocalcin immunoreactivity was observed in secretory granules of both type 1 and type 2 cells. Our findings may indicate that type 1 cells are the main source of hypocalcin, but that type 2 cells also produce it, suggesting that the presence of two cell types reflects different physiological conditions of a single cell type, rather than functionally different cell types. In addition, we summarize our recent data on the localization of other calcium regulatory, or putative calcium regulatory, hormones in fish: parathyroid hormone, calcitonin and calcitonin gene-related peptide.     

Effect of calcitonin on adrenocorticotropic hormone secretion stimulated by corticotropin‐releasing hormone in the hen anterior pituitary

The presence of a receptor for calcitonin (CT) and the effect of chicken CT (cCT) on adrenocorticotropic hormone (ACTH) secretion stimulated by rat/human corticotropin‐releasing hormone (rhCRH) in the hen anterior pituitary were studied. The specific [¹²⁵I]cCT binding component was present in the plasma membrane of hen anterior pituitary and this binding component had properties of a receptor which has binding specificity to cCT, reversibility, saturable binding, high affinity and limited capacity. When anterior pituitary cells were incubated in vitro, cCT increased the maximal secretion of chicken ACTH stimulated by rhCRH. These results suggest that CT may act directly on the anterior pituitary via its receptor binding and enhances the ACTH secretion by CRH.