人胰腺内分泌细胞中CD 57免疫反应性的表达

CD57是一种分子量为110 KD的糖蛋白,它是人类自然杀伤细胞(NK)和杀伤细胞(K)的特异性表面抗原。用它免疫小鼠产生的抗CD57单克隆抗体可特异性识别人的NK 和K 细胞表面抗原。本文应用ABC 免疫组织化学染色结合葡萄糖氧化酶DAB-硫酸镍铵显色技术研究了CD 57在人胰腺的表达和分布。结果发现,CD 57免疫反应(CD 57一IR)细胞主要分布在胰腺的内分泌部(胰岛),偶见于胰腺外分泌部的腺泡和导管上皮中。多数CD 57-IR 细胞呈典型内分泌细胞的形态特征。相邻切片法证明大多数Glu,SS,HPP 和PS 免疫反应细胞呈CD 57阳性。胰腺内神经纤维亦呈CD 57阳性。少数呈CD 57阳性的NK 和K 细胞散布在胰腺结缔组织中。本文对CD 57免疫反应性在人胰腺内分泌细胞中表达的意义进行了讨论。     

Long-term pancreatic duct occlusion impairs the entero-insular axis in the dog--failure of plasma VIP to respond as "incretin"

The response of VIP to either an oral glucose load (OGT) or intravenous glucose (IV glucose), aimed at reproducing the plasma glucose level after OGT, was studied in trained, conscious, sham-operated (Sham; n = 6) dogs, and dogs having initially (12 months before the glucose experiments) undergone occlusion of the pancreatic duct by the prolamine glue technique (Occ; n = 5). As a result, prior to glucose studies, the exocrine pancreas function was found subtotally reduced, as indirectly evaluated by the para-aminobenzoic acid (PABA) test, but no signs of diabetes were detected. The two studies with glucose administration designed to demonstrate the release of insulin, VIP, somatostatin into plasma as modified by enteric signals (represented by the difference of plasma peptide concentration during OGT minus peptide concentration during IV glucose) revealed the following: (1) basal plasma glucose, insulin, VIP, somatostatin did not differ between Sham and Occ dogs; (2) after OGT in Occ dogs the plasma glucose was elevated, whereas plasma insulin was markedly reduced, and VIP, somatostatin were largely unchanged; (3) the integrated output of insulin only was impaired when considering the so-called entero-insulin axis, while integrated VIP, somatostatin were unaltered. It was concluded (a) the Occ procedure in the dog has the capacity to subtotal destruction of the pancreatic acinar tissue, and of the entero-insular axis of insulin, the latter through yet unknown pathways, (b) the Occ technique may be a useful tool for investigation of the nature of "incretin," (c) VIP and somatostatin do not respond to elevated blood glucose and may have no role in the "incretin" concept of enteric modulation of the B-cell.     

3H-methyl scopolamine binding to dispersed pancreatic acini

Summary Maximal amylase release occurred with 10^-5 M carbachol and slightly greater than half maximal response occurred with 3×10^-7 M carbachol in dispersed pancreatic acini. The preparation released more than 45% of its initial amylase content after 60 min of maximal carbachol stimulation. Electron microscopy revealed depletion of zymogen granules and the presence of secretory material in the ductules after carbachol stimulation. At 37° C, maximal binding of methyl scopolamine occurred in about 45 min with 3×10^-10 M ³H-methyl scopolamine. The dissociation constant for ³H-methyl scopolamine was 6.8×10^-10 M and saturation occurred at 109 pm/g protein. The I.C. ₅₀ for ³H-methyl scopolamine inhibition of carbachol-induced amylase secretion was 7 × 10^-10 M.Supported by NIH Biomedical Research Support Grant 5-501-RR-05700-10 and a Grant from the Upjohn Company     

Significance of the peri-insular extracellular matrix for islet isolation from the pancreas of rat,dog, pig,and man

Summary The presence and distribution in the peri-insular region of extracellular matrix, and in particular basement membrane, was investigated in a comparative study comprising pancreata of rat, dog, pig, and man. Basement membrane markers, collagen type-IV and laminin, were determined immunohistochemically. Additional information pertaining to the structural relationships between endocrine and exocrine pancreas, in particular cell-to-cell and cell-to-matrix contacts, was obtained by electron microscopy. In pig, very little periinsular capsule is present, and the structural integration of the porcine islet in the exocrine pancreas almost exclusively depends on cell-to-cell adhesion. In the canine pancreas, the islets are almost completely encapsulated with very little direct exocrine-to-endocrine cell-to-cell contact. In rat and man, the situation is intermediate with a tendency towards predominance of cell-to-matrix adhesion. The intra-insular adhesion mechanisms depend largely on cell-to-cell adhesion in all four species. The ultrastructural results suggest that collagenase preparations employed in islet isolation procedures should be of high purity as to preserve the protease-sensitive intra-islet cell-to-cell adhesion. Under these conditions, however, the endocrine-to-exocrine cell-to-cell contacts will be conserved also, resulting in an exocrine-tissue contamination of the islets of Langerhans. Consequently, additional steps for the effective removal of exocrine tissue and the purification of islets are required.     

江豚(Neophocaena asiaeorientalis)的消化器官Ⅱ. 肠、肝、胰

本篇为江豚(Neophocaena asiaeorientalis)消化器官研究的第二部分。 标本来源见李悦民(1984)。肠的长度和肝的重量都由新鲜标本测得。组织学材料用10%甲醛溶液固定,石蜡包埋,切片用苏木精曙红,PAS和Van Gieson法染色。     

Endodermal expression of Nkx6 genes depends differentially on Pdx1

Nkx family members are essential for normal development of many different tissues such as the heart, lungs, thyroid, prostate, and CNS. Here, we describe the endodermal expression pattern of three Nkx6 family genes of which two shows conserved expression in the early pancreatic epithelium. In chicken, Nkx6.1 expression is not restricted to the presumptive pancreatic area but is more broadly expressed in the endoderm. In mice, expression of Nkx6.1 is restricted to the pancreatic epithelium. In both mice and chicken, Nkx6.2 and Pdx1 are expressed in very similar domains, identifying Nkx6.2 as a novel marker of pancreas endoderm. Additionally, our results show that Nkx6.3 is expressed transiently in pancreatic endoderm in chicken but not mouse embryos. At later stages, Nkx6.3 is found in the caudal stomach and rostral duodenum in both species. Finally, we demonstrate that Pdx1 is required for Nkx6.1 but not Nkx6.2 expression in mice and that ectopic Pdx1 can induce Nkx6.1 but not Nkx6.2 or Nkx6.3 expression in anterior chicken endoderm. These results demonstrate that Nkx6.1 lies downstream of Pdx1 in a genetic pathway and that Pdx1 is required and sufficient for Nkx6.1 expression in the early foregut endoderm.     

Development of the gastrointestinal tract and digestibility of dietary fibre and amino acids in young chickens, ducks and geese fed diets with high amounts of barley

The experiment comprised of 50 chickens, 40 ducks and 30 geese fed a diet containing 40% barley. Birds were kept in metabolic cages from 1 to 42 days of age. A balance trial was carried out during the last week of the bird's life and the apparent digestibility of nutrients was determined. At 21 and 42 days of age 12 animals per species were killed. The absolute length of intestines followed the live weight (LW) of the animals. In relation to metabolic LW (kg(0.67)), the total length was significantly higher in chickens and geese than in ducks at 21 days of age, but identical in the three species at 42 days of age. The absolute and relative weights of intestines were smaller in ducks than in chickens and geese both at 21 and 42 days of age. Dietary fibre was digested better by chickens than by ducks and geese (P<0.01). Ileal digestibility of total amino acids amounted to 76% in chickens, 69% in ducks (P>0.05) and only 56% in geese (P<0.01) with relatively low digestibility of methionine (70, 44 and 52%) and lysine (72, 57 and 41%), respectively. The overall tract-faecal digestibility of total amino acids was evaluated on the level of 86% for all three species and indicates a substantial hind gut synthesis of amino acids.