电离辐射对三维培养条件下人前列腺细胞形态学表现的影响

目的 研究在三维细胞培养条件下前列腺细胞（RWPE-1）腺泡样结构的形成及电离辐射的影响.方法 采用三维培养RWPE-1细胞,Western blot检测自噬相关基因Beclin 1及p53、p21的变化,制备Beclin 1 RNAi表达载体并感染细胞,免疫荧光染色和共聚焦法检测电离辐射作用后细胞形态学变化.结果 三维培养条件下RWPE-1细胞聚积形成腺泡样结构（Acini）,Acini组成细胞出现明显极化,2和5 Gy照射后,Acini结构破坏,少量细胞发生死亡;经Beclin 1基因沉默后,对照组细胞仍呈聚积趋势,2和5 Gy照射后,Acini结构不再形成,细胞发生广泛性死亡.结论 电离辐射抑制RWPE-1细胞Acini结构形成,Beclin 1基因可能在其中发挥一定作用.     

The distribution of membrane bound enzymes in the acini and ducts of the cat pancreas

Summary Enzymes activities of the Na⁺K⁺-and the HCO₃ ^–-ATPases, alkaline phosphatase, amino peptidase and 5 nucleotidase have been measured in 4 different preparations from the cat pancreas a) in the ducts including all sizes b) in ducts of three different diameters c) in that tissue, which had been dissected off from the ducts, called acini, and d) in the whole homogenate of the pancreas. The distribution of the measured enzymes shows, that the Na⁺K⁺-activity is highest in the acinar structures (mean value 0.532 M/mg Protein x h), while the ducts show nearly no Na⁺K⁺-ATPase activity. The HCO₃ ^–-ATPase, the alkaline phosphatase and the 5 nucleotidase are in the ducts between 2.4 and 3.6 times higher than in the whole organ whereas the amino peptidase does not appear to have a selective distribution. As the HCO₃ ^–-ATPase activity distribution pattern is identical with that of the secretory capacity of HCO₃ ^– as evidenced by earlier micropuncture studies, the data suggest that the HCO₃ ^–-ATPase is the main enzyme involved in the secretion of the bicarbonate buffer. Concerning the Na⁺K⁺-ATPase activity in the acinar structures we cannot contribute to its function in the enzyme secreting process.     

The release of intracellular Ca2+ in lacrimal acinar cells by α-, β-adrenergic and muscarinic cholinergic stimulation: the roles of inositol trisphosphate and cyclic ADP-ribose

Stimulation of rat lacrimal acinar cells with acetylcholine (ACh) and the -adrenergic agonist isoprenaline causes a rapid increase in inositol phosphates with 1–4 phosphate groups, resulting in release of Ca²⁺ from intracellular stores. Stimulation with the -adrenergic agonist phenylephrine, however, causes a release of Ca²⁺ from internal stores which is 36% of that observed with ACh stimulation, but without inositol phosphate production. This Ca²⁺ rise was completely inhibited by 100 M ryanodine. Adrenaline (causing activation of both - and -adrenergic receptors) induces a Ca²⁺ release with inositol phosphate synthesis identical to that occuring in the -adrenergic response. Thus, the signalling pathway for -adrenergic stimulation occurs via a path different from that which releases Ca²⁺ via muscarinic cholinergic and -adrenergic stimulation. In permeabilized lacrimal acinar cells cyclic adenosine 5-diphosphoribose (cADP-ribose) and inositol 1,4,5-trisphosphate [Ins(1,4,5)P ₃] cause release of Ca²⁺ from intracellular stores. The Ca²⁺ release evoked by cADP-ribose, but not by Ins(1,4,5)P ₃, was abolished by 100 M ryanodine, implicating a possible involvement of cADP-ribose in phenylephrine-induced Ca²⁺ signalling. When the intracellular free Ca²⁺ concentration ([Ca²⁺]_i) is raised by application of ionomycin, inositol phosphates are synthesized with a half-maximal effect seen at 425 nM. In contrast, loading cells with the Ca²⁺ chelator 1,2-bis(2-aminophenoxy) ethane-N,N,N,N-tetraacetic acid (BAPTA) reduced the adrenaline-induced inositol phosphate synthesis by 27%. The stimulation-induced rise in [Ca²⁺]_i, therefore, appears to cause further synthesis of inositol phosphates, thereby amplifying the receptor-mediated response.     

Foregut mesenchyme contributes cells to pancreatic acini during embryonic development in a chick–quail chimera model

To understand causes of developmental abnormalities of the pancreas, it is essential to understand its normal embryonic development. Current understanding of the development of pancreatic exocrine tissue is that it develops solely from embryonic epithelium, while the role of the surrounding mesenchyme is to signal to this epithelium and form connective tissue. Recent work in our laboratory has shown that pancreatic bud mesenchyme can contribute cells to islets during embryonic development. However, no published studies have investigated in detail whether mesenchyme contributes cells to the exocrine structures of the pancreas. The aim of this study was to investigate whether cells from foregut mesenchyme can contribute to pancreatic acini during embryonic development. Chick–quail chimera recombinant organs were constructed using pancreatic epithelium and mesenchyme from either the pancreas (n=12) or stomach (n=25). These were cultured for 7 days in 3-D collagen gels. The resulting specimens were analysed using morphological criteria and fluorescent immunocytochemistry against pancreatic amylase, insulin, and the quail-specific nucleolar antigen QCPN. Two independent observers determined the origins of acini as either solely epithelial, solely mesenchymal, or of mixed origin. Results are expressed as percentages of total acini identified in each group. Statistical analysis was performed using ² tests (P<0.01 was considered statistically significant). Recombinations of pancreatic epithelium and pancreatic mesenchyme yielded 11 acini, of which 45% were derived from epithelium only, 45% from mesenchyme only, and 10% of mixed origin. Recombinations of pancreatic epithelium and stomach mesenchyme yielded 78 acini, of which 40% were derived from epithelium only, 32% from mesenchyme only, and 28% of mixed origin. When acini with any mesenchymal cellular contribution were considered as a group, there was no significant difference between stomach and pancreatic mesenchymal contribution (P=0.72). This is the first study to demonstrate the cellular contribution of mesenchyme to pancreatic exocrine structures. Our data show that mesenchyme contributes cells to pancreatic acini during development in this model and that mesenchyme derived from stomach and pancreatic sources are both able to form acini.