Beta-endorphin-immunoreactive cells in the human fetal pancreas.

This investigation has been carried out on 50 samples of fetal pancreata from the 10th to the 32nd week of gestation using the PAP technique. beta-Endorphin-reactive cells were morphometrically recorded by means of the point-counting method. beta-Endorphin reactivity occurred for the first time during the 15th week. During further development, beta-endorphin cells were found inside and outside the islets. From the 18th to 23rd week, these cells were primarily localized in the islet periphery. From the 24th week, they rearranged and occurred in irregular positions mixed with other islet cells. This rearrangement took place with a 4 week delay compared with the basic cell types of the islet organ. The extrainsular portion of these cells in the exocrine parenchyma varied between 0.3% in the 27th week and up to 10% in the 22nd week. Concerning the adult human pancreas, it has been suggested whether beta-endorphin cells may be a 6th basic cell type of the islet organ. Previous studies on the coexistence of somatostatin, glucagon and beta-endorphin in the same islet cell and the morphometric analysis would support this assumption. Biochemical examinations indicate that beta-endorphin is a modulator of insulin, glucagon, and somatostatin secretion in the islet organ. This is supported by the fact that beta-endorphin cells have extended cell bodies which is typical of cells with paracrine function.

Detection of proinsulin, C-peptide, insulin-A-chain, and glicentin in pancreatic islet cells of early human fetogenesis.

The presence of C-peptide, proinsulin, insulin-A-chain, and glicentin in human fetal pancreatic cells by using the PAP-technique was investigated and the results obtained compared with the occurrence of insulin or glucagon immunoreactive cells. In pancreatic sections obtained from 10 weeks old human fetuses we could identify cells reacting with antibodies directed against C-peptide, proinsulin, and insulin-A-chain. The majority of the cells were found in the duct epithelium and their number increased from the 10th to 14th week forming clusters near the ducts. The number and localization of the cells correspond exactly to the insulin positive cells. The presence of proinsulin and insulin-A-chains is a further proof of biological activity already in an early step of fetal development. The presence of glicentin-positive cells in the 10th week of gestational age as well as cells reacting with glucagon antibodies provide evidence for active glucagon biosynthesis. The number of these cells increased markedly in the 14th week of gestational age.

Immunohistochemical investigations of beta-endorphin in human pancreatic islets.

The PAP technique was used to examine adult human pancreata (corpus) immunohistochemically for the presence of beta-endorphin containing cells. These cells were found to account for 4.8% of the islet cells. They are irregularly distributed within the islets, where they occur singly or in groups of 3 to 5 cells between the acini (0.4% of the parenchyma). Investigations designed to detect the simultaneous presence of beta-endorphin and somatostatin or glucagon revealed that beta-endorphin occurs in somatostatin cells (1.0% of the islet parenchyma). This is the 1st proof that these 2 hormones appear together. The simultaneous presence of beta-endorphin and glucagon in the same cell was also observed in 0.9% of the islet parenchyma. Earlier studies undertaken by us have shown that beta-endorphin is synthetized in the islets of Langerhans. Possible functions of beta-endorphin in the islets are discussed.

Neuron-specific enolase (NSE) as a neuroendocrine cell marker in the human fetal pancreas.

Using the PAP technique, we investigated the presence of neuron-specific enolase in the human fetal pancreas of 10, 12, and 14 weeks of gestational age. Neuron-specific enolase is present in the islet cells in the 10th week. Positive cells are situated mainly in duct epithelium. The number of cells with a positive reaction increases from the 12th to the 14th week. In the 14th week, they are clustered either near the ducts or between the acini. The numbers and localizations of the cells correspond to those obtained in previous studies with 4 basic islet cell types in the same material. The present results are a further proof that islet cells are biologically active during early fetal development.

[Morphological studies of the effect of chromium-III-chloride on the islet cell organ in rats under the conditions of high and low fat diets]. / Morphologische Untersuchungen zur Wirkung von Chrom-III-Chlorid auf das Inselzellorgan bei Ratten unter den Bedingungen einer Hochfett- und einer Niedrigfettdiät.

It is well known, that the glucose tolerance factor amplifies the peripheral action of insulin. This factor contains trivalent chromium. This investigation deals with the influence of trivalent chromium on morphometric and histological parameters of pancreatic islets of wistar rats. Animals were given chromium-III-chloride for 8 weeks (perorally, daily 15 ppm or 3 ppm) under conditions of high (HFD) and low (LFD) fat diet. Staining of pancreatic slices was performed with Victoria blue and acid Fuchsin. The relative volume density of the endocrine cells was obtained as the ratio of the number of islet cells to the number of exocrine pancreatic cells. The statistical evaluation was performed by using Students t-test. In HFD animals (n = 12) chromium supplementation caused an increase by 41% of volume of islets compared to HFD controls. A lot of small islets were found, which may be newly formed. Moreover, polynesia and hyperplasia of islets were observed. LFD animals (n = 12) do not show any morphometric changes in comparison with LED controls; but macronesia, micronesia and polynesia of islets were observed. In conclusion we suggest, that under special conditions trivalent chromium has growth stimulatory effects on the endocrine pancreas.

[Immunocytochemical studies of the development of basal cell types of human islet organs]. / Immunzytochemische Untersuchungen zur Entwicklung der Grundzelltypen des menschlichen Inselorgans.

The investigations are carried out in 19 human fetal pancreases. The detection of the 4 islet hormones insulin, glucagon, somatostatin and PP ist carried out in PAP-technique. The parts of these 4 types of islet cells are estimated quantitatively. In the 10th to 15th week of development insulin-producing B-cells are present. Moreover glucagon-, somatostatin- and PP-cells in the islet organ are present. In the group of 16th to 20th week of gestation insulin-, glucagon- and somatostatin-cells are increased compared to the first group. PP-cells are not altered. The increase of 3 types of islet cells is a result of fetal development.

Tissue cultivation as a method for preservation of human foetal islet parenchyma--a correlated biochemical, immunohistochemical and morphometric investigation.

Tissue culture of human foetal pancreas slices, obtained at a gestational age between 10 and 19 weeks, as a method of preservation and to pool the material before transplantation was investigated. Before and after 2 weeks of culture the pancreatic insulin content, the insulin secretion in response to glucose and isobutylmethylxanthin (IBMX) as well as the protein biosynthesis were measured. In addition, the distribution of the insulin immunoreactive cells was examined, as well as their relative volume density. After 2 weeks' culture an increase of the basal insulin secretion was observed; this was probably due to the glucose content (10 mmol/l) in the culture medium. Neither the stimulated insulin secretion, nor the protein biosynthesis, the insulin content, and the B-cell volume were altered by the used culture conditions. It was concluded that tissue culture is a suitable method to preserve human foetal pancreas slices before transplantation.

[Quantitative histochemical study of pancreatic islets of sand rats (Psammomys obesus) in diabetes mellitus I. Cytophotometric measurement of insulin content]. / Quantitativ-histochemische Untersuchungen an Langerhansschen Inseln von Sandratten (Psammomys obesus) während der Ausbildung eines Diabetes mellitus. I. Cytophotometrische Messung des Insulingehalts.

The insulin-content in islets of Langerhans on sand rats with disturbances of the carbon hydrate tolerance (reference-, impaired glucose tolerance-, and diabetic group) is measured cytophotometrically. In the IGT-group (impaired glucose tolerance) is a decrease of the insulin content in B-cells detectable. However in the diabetic group of sand rats is the insulin-content increased. This results demonstrate the stimulation of the B-cell function in the islets of Langerhans. The diabetes mellitus of sand rats is characterized by disturbed glucose tolerance hyperinsulinaemia, and elevated readiness to insulin secretion. That are characteristics of the human type-II-diabetes (insulin-independent). In conclusion, the sand rat is a biological model of the human type-II-diabetes (NIDDM).

[Quantitative histologic studies of mast cells in the parathyroid gland of sand rats (Psammomys obesus) during the development of a mellitus syndrome]. / Quantitativ-histologische Untersuchungen an Mastzellen in der Glandula parathyreoidea von Sandratten (Psammomys obesus) während der Ausbildung eines Mellitus-Syndroms.

Mast cells in the parathyroid glands of sand rats with different disturbances of the carbon hydrate tolerance (reference, impaired-glucose-tolerance, and diabetic group) are quantitative-histologically investigated. In the IGT-group (impaired glucose tolerance), mast cells are significantly increased. However, the number of this cells in the diabetic group is significantly decreased. This investigations demonstrate that the mellitus-syndrome is not only a complex neuroendocrine disturbance but also a disturbance of biogenic amines and the organ of the connective tissue.

[A-cell-hyperplasia of islets of Langerhans on rabbits after immunisation with glucagon (author's transl)]. / A-Zellenhyperplasie der Langerhansschen Inseln von Kaninchen nach Immunisierung mit Glukagon.

Rabbits are immunized with glucagon for the production of anti-glucagonsera. Pancreatic islets of 9 animals are investigated histochemically. In the islets of immunized rabbits is a hyperplasia of A-cells detected. Singular islets consist only of A-cells.

Electron-microscopical investigations on adenohypophyses in sand rats (Psammomys obesus) before manifestation of diabetes mellitus).

The experiments have been carried out on the adenohypophyses of 20 sand rats (6 so called protodiabetic, 6 diabetic animals and 8 animals as control group). Of those cell types known in hypophyses alpha-(STH-)cells, prolactin (LTH-)cells, beta-(FSH-) cells, gamma-(LH-)cells and delta-(TSH-)cells were shown to exist in the hypophyses of the control group. -- The size of the granula of these cell types in the sand rats also corresponds to the values known from other rodents. A reduction of granular density could be noticed in the alpha-cells of the so called protodiabetic group as well as in the prolactin cells. The Golgi apparatus is prominent, and the mitochondria have grown and multiplied. The other cell types show no peculiarities. Changes were also found in the alpha- and prolactin cells of the diabetic group: The granula are diminished very much (more in the prolactin cells than in the alpha-cells), the ergastoplasm is much increased and has dense colonies of ribosomes. The Golgi apparatus is highly developed. These experiments prove ultrastructural changes in the cell types of the adenohypophyses not only in the state of a mellitus-like syndrome in sand rats but also during adaptation to laboratory holding of these animals. It is suggested that during adaptation to laboratory holding in a state of pronounced increase of body weight and in the state of a mellitus-like syndrome in sand rats the alpha-cells of the adenohypophyses are stimulated as well as the prolactin cells.

[Morphological characterization of the islets of langerhans in metabolically healthy C57BL KsJ mice]. / Zur morphologischen Charakterisierung der Langerhansschen Inseln von stoffwechselgesunden C57BL KsJ-Mausen.

The islets of Langerhans of metabolic healthy C57 BL KsJ mice have been characterized morphologically. By it they showed structures typical for Muridae as far as the A-cells formed a mostly single-layered shell around the compact complex of B-cells situated centrally. The electron-microscopical investigations rendered possible a well defined differentiation between A-, B-, and D-cells and also demonstrated no fundamental structural differences in comparison with the conditions existing in other rodents.

[Immunohistochemical detection of somatostatin in the islet-organ of sand rats (Psammomys obesus) (author's transl)]. / Immunohistochemischer Nachweis von Somatostatin im Inselorgan von Sandratten (Psammomys obesus).

Islets of Langerhans were investigated with the indirect immunofluorescence technique for somatostatin. Fluorescence was observed in cells which are by number and localization typical "D-cells". somatostatin-like immunoreactivity was also present in few cells of the exocrine part of pancreas.

[Occurrence of glycogen-deposites in acinar cells of pancreas in prediabetic sand rats (Psammomys obesus) (author's transl)]. / Das Vorkommen von Glykogenablagerungen in Acinuszellen des Pankreas prädiabetischer Sandratten (Psammonys obesus).

The investigations were in 6 prediabetic and 8 normoglycemic sand rats carried out with a histochemical method (PAS-reaction). Glycogen is present in pancreatic acinar cells in various quantity. It is in the cytoplasm homogenously distributed. The PAS positive acini are near the islets of Langerhans localized, which have in their B cells also glycogen deposites. The phenomenon is by the vascularisation of the pancreas explained.