Immunocytochemical study of argyrophil (Sevier Munger) endocrine cells of adult human pancreas

Bouin-fixed tissues from non-diabetic adult human pancreata display an argyrophil reaction mainly in the periphery of the islets with the silver technique of Sevier-Munger. The nature of these argyrophil cells was examined after restaining by an indirect immunocytochemical method using antibodies against insulin, glucagon, somatostatin and pancreatic polypeptide. After this procedure the argyrophil cells were identified as glucagon (A-) cells and pancreatic polypeptide (PP-) cells, although the latter exhibited a weaker reaction. The insulin (B-) cells and somatostatin (D-) cells were unreactive. The results show that the Seiver-Munger stain is of equal value to the Grimelius silver nitrate stain in adult human pancreatic islets after fixation in Bouin's fluid.     

Immunocytochemical study of argyrophil (Sevier Munger) endocrine cells of adult human pancreas

Summary Bouin-fixed tissues from non-diabetic adult human pancreata display an argyrophil reaction mainly in the periphery of the islets with the silver technique of Sevier-Munger. The nature of these argyrophil cells was examined after restaining by an indirect immunocytochemical method using antibodies against insulin, glucagon, somatostatin and pancreatic polypeptide. After this procedure the argyrophil cells were identified as glucagon (A-) cells and pancreatic polypeptide (PP-) cells, although the latter exhibited a weaker reaction. The insulin (B-) cells and somatostatin (D-) cells were unreactive. The results show that the Sevier-Munger stain is of equal value to the Grimelius silver nitrate stain in adult human pancreatic islets after fixation in Bouin's fluid.Supported by grants from the Swedish Medical Research Council (Project No. 102)     

Polyhormonal aspect of the endocrine cells of the human fetal pancreas

Histological studies were performed on 30 pancreases obtained from normal human fetuses aged between the 9th and 38th week. For immunocytochemistry, the avidin-biotin-peroxidase method was used to identify and colocalise insulin, glucagon, somatostatin, pancreatic polypeptide and proliferating cell nuclear antigen. In the 9th week, cells containing all investigated peptides were present. During the fetal period, two populations of endocrine cells have been distinguished, Langerhans islets and freely dispersed cells. The free cells were polyhormonal, containing insulin, glucagon, somatostatin and pancreatic polypeptide, and were localised in the walls of pancreatic ducts throughout the whole gland. During the development of the islets we have observed four stages: (1) the scattered polyhormonal cell stage (9th–10th week), (2) the immature polyhormonal islet stage (11th–15th week), (3) the insulin monohormonal core islet stage (16th–29th week), in which zonular and mantle islets are observed, and (4) the polymorphic islet stage (from the 30th week onwards), which is characterised by the presence of monohormonal cells expressing glucagon or somatostatin. Bigeminal and polar islets also appeared during this last stage. The islets consisted of an insulin core surrounded by a thick (in the part developing from the dorsal primordium) or thin rim (part of the pancreas concerned with the ventral primordium) of intermingled mono- or dihormonal glucagon-positive or somatostatin-positive cells. The most externally located polyhormonal cells exhibited a reaction for glucagon, somatostatin and pancreatic polypeptide. Apart from the above-mentioned types of islets, all arrangements observed in earlier stages were present. Proliferating cell nuclear antigen-positive cells (single in the large islets and more numerous in the smaller ones) were predominantly observed in the outermost layer. Taken together our data indicate that, during the human prenatal development of the islet, endocrine cells are able to synthesise several different hormones. Maturation of these cells involved or depended on a change from a polyhormonal to a monohormonal state and is concerned with decreasing proliferative capacity. This supports the concept of a common precursor stem cell for the hormone-producing cells of the fetal human pancreas. Accepted: 1 June 1999     

The respiratory system of the genusCallithrix,the South American monkey

It has been described the cytology of the following parts of the respiratory system of some South American primates:Callithrix jacchus andCallithrix argentata melanura. The nasal cavities are divided into three parts: a vestibule, covered with a stratified nonkeratinized squamous epithelium; the respiratory portion, consisting of a pseudostratified columnar ciliated epithelium with goblet cells and the olfactory portion which is also covered with a high respiratory epithelium without goblet cells. The trachea is lined with a mucous membrane, whose epithelium is pseudostratified columnar ciliated with scarce goblet cells in the proximal portion unlike to the distal one. In the dorsal portion of the trachea, at the level of the gap between the two ends of incomplete cartilaginous rings, the epithelial lining is of transitional type. The incomplete hyaline cartilaginous rings present centers of calcification. The right and left lungs consist of two and three lobes respectively characteristic for these species, but they are not divided into lobules by connective tissue as in other ones. The bronchi, bronchioles and the respiratory portion, respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli present the typical respiratory structure with exception of their cartilaginous configuration; the cartilage continues as far as the respiratory bronchioles and alveolar ducts. These last structures are formed by a thin squamous epithelium, in which we observed two types of alveolar lining cells. This work was supported by grants from the Consejo Nacional de Investigaciones Cientificas y Técnicas (CONICET) and EHIGE program. Postgraduated fellow from CONICET. established Investigator and Director of EHIGE (Estudio Histológico comparado del Sistema de Glándulas Endócrinas) from CONICET.     

Immunocytochemical localization of hormone-producing cells within the pancreatic islets of the rainbow trout (Salmo gairdneri)

Summary A histological study of the pancreatic islets in rainbow trout, Salmo gairdneri, was undertaken in which polypeptide hormone-producing cells were localized, using immunocytochemical staining techniques. Four different celltypes were identified in this manner. These were the insulin, somatostatin, pancreatic polypeptide and glucagon/gastric inhibitory polypeptide (GIP) cells. The glucagon/GIP cell was designated thus as antisera to both hormones crossreacted with a common population of cells. A fifth cell-type, commonly referred to as a clear cell, was also identified although its secretory product is as yet undetermined. These functional cell types were compared to the standard tinctorial properties of pancreatic endocrine cells. The relationships of the various cell types with each other was also observed.     

Distribution and frequency of endocrine cells in the pancreas of the ddY mouse: an immunohistochemical study

The regional distribution and frequency of pancreatic endocrine cells in ddY mice were studied by an immunohistochemical (peroxidase anti-peroxidase; PAP) method using four types of specific antisera against insulin, glucagon, somatostatin and human pancreatic polypeptide (hPP). In the pancreatic islets, most of insulin-immunoreactive (IR) cells were located in the central portion. Most of glucagon- and somatostatin-IR cells were observed in peripheral regions although a somewhat smaller number of cells were also located in the central regions. HPP-IR cells were randomly distributed throughout the entire islets. In the exocrine pancreas, insulin-, glucagon-, somatostatin- and hPP-IR cells were detected; they occurred mainly among the exocrine parenchyma as solitary cells. Cell clusters consisted of only insulin- or only glucagon-IR cells and were distributed in the pancreas parenchyma as small islets. In addition, insulin- and glucagon-IR cells were also demonstrated in the pancreatic duct regions. Insulin-IR cells were located in the epithelium and sub-epithelial connective tissue regions as solitary cells and/or clusters (3-4 cells), and glucagon-IR cells were mainly located in the epithelium as solitary cells. Overall, there were 63.89+/-5.39% insulin-, 26.52+/-3.55% glucagon-, 7.25+/-2.83% somatostatin- and 1.90+/-0.58% hPP-IR cells. In conclusion, some strain-dependent characteristic distributional patterns of pancreatic endocrine cells were found in the ddY mouse.     

Light and electron microscopical immunocytochemical localization of pancreastatin-like immunoreactivity in porcine tissues

Pancreastatin is a 49 amino acid comprising peptide isolated from porcine pancreas that is derived by proteolytic processing from chromogranin A. Using an antibody against the synthetic C-terminal fragment pancreastatin (33-49), we examined the light and electron microscopical immunocytochemical localization of this peptide in porcine tissues. Pancreastatin-like immunoreactivity (PLI) was found in pancreatic somatostatin-, insulin- and glucagon cells in varying intensities; pancreatic polypeptide cells were always negative. At the electron microscopical (EM) level the immunoreactivity was confined to the electron dense core of the secretory granules in the case of somatostatin and insulin cells or to the less electron dense "halo" of the glucagon granules. In the antrum PLI positive cells represented gastrin (G), somatostatin (D) and enterochromaffin (EC) cells, in the duodenum in addition to EC- and G-cells a small number of PLI positive cells showed a positive immunoreaction for glucagon-like peptide (GLP) I and secretin in serial sections. Both norepinephrine and epinephrine containing cells of the adrenal medulla exhibited a strong reaction for PLI. In the pituitary several cell populations stained with varying intensities, including gonadotrophs and thyrotrophys. PLI is present in a distinct and characteristic subpopulation of neuroendocrine cells in various organs. The subcellular localization may indicate a function in the granular concentration, packaging and storage of peptides and amines in the brain-gut endocrine system.     

Fetal and neonatal rat pancreas in organ culture: age-related effects of corticosterone on the development of the islet cells

Fetal (18 days postcoitum) and neonatal (3-day) pancreatic explants were grown in organ culture with or without supplementation with corticosterone (0.1 micrograms/ml). After 0, 4, and 8 days of culture, the specific hormone-positive, islet cell volumes were determined by the use of immunocytochemical and morphometric methods. The insulin, glucagon, and somatostatin contents of the explants were estimated by radioimmunoassays. In the fetal explants, all of the islet cell populations increased in volume and the content of each of the hormones increased over an 8-day period of culture. Supplementation with corticosterone resulted in a restriction of the increases of the alpha and delta cell volumes and in the somatostatin content of the explants. In the neonatal explants, the volumes of the alpha and delta cells and the glucagon and somatostatin contents decreased over a 4-day culture period. The presence of corticosterone in the culture medium preserved these cells and their hormone content. Co-culture of 18-day fetal and 3-day neonatal pancreata in control medium for 8 days resulted in a significant decrease in the content of all three of the islet hormones in the fetal explants. These results suggest that a substance harmful to the islet cells is released from the degenerating acinar cells. Thus, the effects of the steroid on the islets may be mediated through its effects on the acinar tissue.     

The endocrine cells in the gastroenteropancreatic system of the bowfin, Amia calva L.: an immunohistochemical, ultrastructural, and immunocytochemical analysis.

The gastroenteropancreatic (GEP) endocrine system of bowfin (Amia calva) was described using light and electron microscopy and immunological methods. The islet organ (endocrine pancreas) consists of diffusely scattered, mostly small islets and isolated patches of cells among and within the exocrine acini. The islets are composed of abundant, centrally located B cells immunoreactive to bovine and lamprey insulin antisera and D cells showing a widespread distribution and specificity to somatostatin antibodies. A and F cells are present at the very periphery of the islets and are immunoreactive with antisera against glucagon (and glucagon-like peptide) and several peptides of the pancreatic polypeptide (PP)-family, respectively. The peptides of the two families usually collocates within the same peripheral islet cells and are the most common immunoreactive peptides present in the extra-islet tissue. Immunocytochemistry and fine structural observations characterised the granule morphology for B and D cells and identified two cell types with granules immunoreactive to glucagon antisera. These two putative A cells had similar granules, which were distinct from either B or D cells, but one of the cells had rod-shaped cytoplasmic inclusions within cisternae of what appeared to be rough endoplasmic reticulum. The inclusions were not immunoreactive to either insulin or glucagon antisera. Only small numbers of cells in the stomach and intestine immunoreacted to antisera against somatostatin, glucagon, and PP-family peptides. The paucity of these cells was reflected in the low concentrations of these peptides in intestinal extracts. The GEP system of bowfin is not unlike that of other actinopterygian fishes, but there are some marked differences that may reflect the antiquity of this system and/or may be a consequence of the ontogeny of this system in this species.     

Immunocytochemical study of the distribuition of endocrine cells in the pancreas of the Brazilian sparrow species Zonotrichia Capensis Subtorquata (Swaison, 1837).

In the present study, we investigated types of pancreatic endocrine cells and its respective peptides in the Brazilian sparrow species using immunocytochemistry. The use of polyclonal specific antisera for somatostatin, glucagon, avian pancreatic polypeptide (APP), YY polypeptide (PYY) and insulin, revealed a diversified distribution in the pancreas. All these types of immunoreactive cells were observed in the pancreas with different amounts. Insulin-Immunoreactive cells to (B cells) were most numerous, preferably occupying the central place in the pancreatic islets. Somatostatin, PPA, PYY and glucagon immunoreactive cells occurred in a lower frequency in the periphery of pancreatic islets.     

Immunohistochemical study of the developing endocrine pancreas of the opossum (Didelphis virginiana)

Cells immunoreactive for insulin, glucagon, somatostatin, bovine pancreatic polypeptide and 5-hydroxytryptamine are found in the pancreas of the newborn opossum and of all later stages examined. All immunoreactive cell types are present in primary and secondary islets and within elements of the exocrine pancreas. Cells immunoreactive for glucagon, bovine pancreatic polypeptide, somatostatin and 5-hydroxytryptamine generally are confined to the periphery of secondary (intralobular) islets, whereas insulin-immunoreactive cells occupy the central region. Endocrine cells within primary (interlobular) islets are randomly scattered. A small number of pancreatic-polypeptide-immunoreactive cells are reactive for the amine 5-hydroxytryptamine also, but the reverse is not observed. The endocrine pancreas continues to differentiate and develop throughout postnatal life and into adulthood. Little difference was observed between the head and tail regions of the opossum pancreas for the measurements made.     

Light and electron microscopical immunocytochemical localization of pancreastatin-like immunoreactivity in porcine tissues

Summary Pancreastatin is a 49 amino acid comprising peptide isolated from porcine pancreas that is derived by proteolytic processing from chromogranin A. Using an antibody against the synthetic C-terminal fragment pancreastatin (33–49), we examined the light and electron microscopical immunocytochemical localization of this peptide in porcine tissues. Pancreastatin-like immunoreactivity (PLI) was found in pancreatic somatostatin-, insulin- and glucagon cells in varying intensities; pancreatic polypeptide cells were always negative. At the electron microscopical (EM) level the immunoreactivity was confined to the electron dense core of the secretory granules in the case of somatostatin and insulin cells or to the less electron dense halo of the glucagon granules. In the antrum PLI positive cells represented gastrin (G), somatostatin (D) and enterochromaffin (EC) cells, in the duodenum in addition to EC- and G-cells a small number of PLI positive cells showed a positive immunoreaction for glucagon-like peptide (GLP) I and secretin in serial sections. Both norepinephrine and epinephrine containing cells of the adrenal medulla exhibited a strong reaction for PLI. In the pituitary several cell populations stained with varying intensities, including gonadotrophs and thyrotrophs. PLI is present in a distinct and characteristic subpopulation of neuroendocrine cells in various organs. The subcellular localization may indicate a function in the granular concentration, packaging and storage of peptides and amines in the brain-gut endocrine system.     

胰岛淀粉样多肽在豚鼠胰腺分布的免疫组织化学研究

本文用免疫组织化学ＡＢＣ法,研究了胰岛淀粉样多肽（Ｉｓｌｅｔａｍｙｌｏｉｄｐｏｌｙｐｅｐｔｉｄｅ,ＩＡＰＰ或称Ａｍｙｌｉｎ）在豚鼠胰脏的分布,并用邻片免疫组织化学双标记法,观察了ＩＡＰＰ与胰岛素（Ｉｎｓｕｌｉｎ,ＩＮＳ）、生长抑素（ＳｏｍａｔｏｓｔａｔｉｎＳＳ）的共存关系。结果显示,豚鼠胰岛内绝大多数细胞都呈ＩＡＰＰ阳性免疫反应,在胰外分泌部的腺泡和导管内也散在分布有ＩＡＰＰ免疫反应阳性细胞。多数ＩＡＰＰ免疫反应阳性的细胞都显示ＩＮＳ免疫反应阳性,胰岛内少数ＩＡＰＰ阳性细胞也呈ＳＳ免疫反应阳性。说明ＩＡＰＰ主要分布在豚鼠的胰岛内．但也少量存在于外分泌部。ＩＡＰＰ主要和ＩＮＳ共存于Ｂ细胞内。但也和ＳＳ共存于Ｄ细胞内,提示ＩＡＰＰ可能通过自分泌途径调节ＩＮＳ和ＳＳ的分泌。     

Modulation of somatostatin release by endogenous glucagon and insulin: physiological relationship between A, B and D cells in rat pancreatic islets

In order to understand the physiological role of endogenous insulin or glucagon in somatostatin release, isolated rat pancreatic islets were treated with antiinsulin or antiglucagon antiserum in the presence of physiological amounts of glucose. The release of somatostatin was unchanged by treatment with antiinsulin antiserum which neutralized insulin released by 3.3, 8.3 and 16.7 mM of glucose. However, somatostatin release after treatment with antiglucagon antiserum was much reduced at all concentrations of glucose when compared with the release from control serum. Exogenous rat insulin (0.11, 1.11 micrograms/ml) had no effect, but exogenous glucagon (1, 5 micrograms/ml) resulted in a significant increase. Somatostatin release was stimulated by glucose, but the effect was insignificant. These results clearly indicate the physiological role of endogenous glucagon in the modulation of somatostatin release from the islets of Langerhans. Furthermore, the physiological relationship between A, B and D cells may be mediated through the paracrine mechanism.     

Oral administration of somatostatin reduces postprandial plasma triglycerides, gastrin and gut glucagon-like immunoreactivity.

The present study was designed to determine if orally administered somatostatin can reduce the postprandial rise in plasma triglycerides, gastrin, gut glucagon-like immunoreactivity (GLI) and the pancreatic hormones insulin and glucagon. Ten overnight fasted dogs were fed a fat-protein meal with or without 2 mg synthetic somatostatin, followed by another 2 mg somatostatin 90 min later. After the meal with somatostatin, postprandial plasma triglyceride levels were significantly lower for 5 hours, GLI levels for 3.5 hours and gastrin levels for 1 hour compared to the controls. Plasma insulin, glucagon and somatostatin-like immunoreactivity was not different from the control experiments. It is concluded that orally administered somatostatin lowers the postprandial levels of triglycerides, GLI and gastrin in dogs. This may have therapeutic implications for the management of gastrointestinal and metabolic disorders.     

Porcine islet isolation, cellular composition and secretory response

Porcine islets were isolated by infusion of a warm collagenase solution into whole pancreata followed by static incubation at 37 degrees C for 15 minutes. The pancreata were then chopped into small pieces and the free islets purified by filtration and centrifugation over a ficoll gradient. The insulin:amylase ratio of the islets compared to that in the intact pancreas was determined in 19 pancreata and indicates that the isolated islets were of a high degree of purity. The distribution of insulin, glucagon, somatostatin and pancreatic polypeptide containing cells in pig pancreas sections was compared with that in rat. Porcine islets were much smaller and less well defined than rat islets with infiltration of acinar material even into the islet core. The levels of insulin, glucagon and somatostatin in porcine pancreas and isolated porcine islets were measured using conventional radioimmunoassay techniques. The ratio of these hormones in the pancreas was 105.1:5.8:1 respectively, and in the islets 105.1:0.68:0.087 respectively. Fragmentation of the islets during the isolation may have led to the loss of glucagon and somatostatin-containing cells. Islets cultured overnight and tested with a range of glucose concentrations for one hour did not show a significant stimulation of insulin secretion in the presence of 8.3 mM or 16.7 mM glucose compared to that in 2.8 mM glucose. However freshly isolated islets challenged with 8.3 mM, 13.9 mM and 22.2 mM glucose showed a 1.8 fold, 2.0 fold and 2.3 fold response respectively, over that in 2.8 mM glucose.(ABSTRACT TRUNCATED AT 250 WORDS)     

Experimental study on the origin of pancreatic endocrine cells in the toad Bufo bufo L.

Summary Ablation, transplantation and culture experiments were used to determine the respective roles of the pancreatic dorsal and ventral anlagen in the formation of the endocrine cells. Three successive waves of endocrine formation occur in the pancreas of Bufo bufo at three developmental stages (III₆, IV₁ and IV₂). Each wave is derived from a different source: the first originates from the dorsal anlage, the second from the exocrine tissue of the cortex of the pancreas and the third from the pancreatic duct. Each generation of islets has a specific composition of different cell types. The first wave is only composed of insulin islets; the second wave gives rise to single insulin, glucagon and somatostatin cells; while the third wave generates single cells synthesizing one of the three hormones, homogeneous islets of insulin cells, rare glucagon islets and heterogeneous islets containing insulin cells in the centre and a few glucagon or somatostatin cells at the periphery.     

Glycogen in pancreatic islets of steroid diabetic rats

Summary In the islets of the rat pancreas, steroid diabetes induced by triamcinolon-acetonid leads to degranulation of the B cells and glycogen infiltration. The glycogen cannot be satisfactorily detected using methods like the chromic acid technique according to Bauer, staining with Best's carmine, or the usually applied periodic acid-Schiff (PAS) reaction. Glycogen detection is improved, however, when lead tetraacetate is used in place of periodic acid as oxidizing agent. When combining the carbohydrate detection method with the peroxidase — antiperoxidase (PAP) method used for immunocytochemical detection of the various pancreatic islet hormones, paraffin sections reveal that glycogen is primarily localized in granulated B cells; the degranulated B cells also contain glycogen, though in smaller amounts. In contrast, the islet cells containing somatostatin, glucagon and pancreatic polypeptide are nearly free of glycogen.This study was supported by the Deutsche Forschungsgemeinschaft K1 426/2     

Immunofluorescent localization of secretin in pancreatic monolayer culture

Summary Immunofluorescent cells to synthetic secretin were identified in monolayer culture of neonatal rat pancreas. No cross reaction of anti-secretin was observed with either glucagon, somatostatin or gastrin. The presence of cells containing secretin or a secretin-like peptide adds a new cell type to the three already characterized (insulin, glucagon and somatostatin containing cells) in monolayer culture.This work was supported by a grant (no. 3.553.75) from the Fonds National Suisse de la Recherche Scientifique, and a grant for cancer research from the Ministry of Public Welfare of Japan