Cytoarchitectural features of Ucides cordatus (Crustacea Decapoda) hepatopancreas:: structure and elemental composition of electron-dense granules
Cytoarchitectural features of Ucides cordatus (Crustacea Decapoda) hepatopancreas:: structure and elemental composition of electron-dense granules
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DOI：
10.1016/s0040816602000101
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发表时间：
2002-10-01
期刊：
影响因子：
2.6
通讯作者：
Allodi, S
中科院分区：
文献类型：
--
作者：
Correa, JD;Farina, M;Allodi, S
本文用光学显微镜和电子显微镜对中华绒螯蟹的肝胰腺组织进行了观察。观察到的上皮细胞是：E-细胞（胚胎），位于肝胰腺小管的远端部分，R-细胞（吸收）F-细胞（纤维状）和B-细胞（水泡或分泌），发现在其中间和近端区域。在肝胰管近端细胞中，经常发现两种类型的电子致密颗粒（EDG）。两种类型的EDG呈现交替的同心电子致密层和电子透明层。为了更好地表征这些颗粒，进行能量色散X射线分析（EDXA）和葡萄糖-6-磷酸酶（G6 β）细胞化学。一种类型的球形颗粒内被髓鞘样膜以及一些小的膜结合囊泡包围的空泡。这类颗粒在EDXA谱上既没有可检测到的Ca和P，也没有G6 S细胞化学反应产物。第二类颗粒具有O、P和Ca特征峰。G6 β细胞化学产物在这些结构内观察到，并表明这种矿化型被内质网膜包围。这一结果表明，在美国。内质网与矿化EDG的发生有关。虽然无定形矿物颗粒可能与新甲壳合成的钙和磷的储存有关，但由非矿化球形多层膜覆盖的EDG可能与晚期内体有关。然而，在上皮近端部分没有确定EDG的特异性分泌途径。(C)2002爱思唯尔科技有限公司版权所有。
Hepatopancreal tissue of the crab Ucides cordatus was investigated by light and electron microscopy. The observed epithelial cells were: E-cells (embryonic), located in the distal portion of the hepatopancreal tubules, R-cells (resorptive) F-cells (fibrillar) and B-cells (blister or secretory), found in its intermediate and proximal regions. Two types of electron-dense granules (EDGs) were found frequently in the cells of the proximal portion of the hepatopancreal tubule. Both types of EDGs presented alternating concentric electron-dense and electron-lucent layers. In order to better characterize these granules, energy dispersive X-ray analysis (EDXA) and glucose-6-phosphatase (G6Pase) cytochemistry were performed. One type of spherical granule was seen inside vacuoles surrounded by an association of myelin-like membranes as well as some small membrane-bound vesicles. This type of granule neither presented detectable Ca and P on EDXA spectra nor G6Pase cytochemical reaction products. The second type of granule had O, P and Ca characteristic peaks. G6Pase cytochemical products were observed inside these structures and showed that this mineralized type was surrounded by endloplasmic reticulum membranes. This result suggests that in U. cordatus the endoplasmic reticulum is associated with the genesis of mineralized EDGs. While amorphous mineral granules may be associated with a storage of Ca and P for the new carapace synthesis, EDGs covered by the nonmineralized spherical multi-layered membranes may be associated with late endosomes. No specific secretory pathway however was determined for the EDGs at the epithelial proximal portion. (C) 2002 Elsevier Science Ltd. All rights reserved.