[Morphologic and biochemical characterization of the Islets of Langerhans of C57BL/KsJ-mice treated with glibenclamid and glucose]. / Zur morphologischen und biochemischen Charakterisierung der Langerhansschen Inseln von mit Glibenclamid und Glukose belasteten C57BL/KsJ-Mäusen.

From the findings of our investigations can be concluded that after long-lasting in vivo gifts of glibenclamid and glucose a decrease of the glucose-induced secretion of insulin in the B-cells of the islets of Langerhans is resulting. After strong experimental stimulation during the existence of an abnormal metabolic situation the synthesis of insulin had not been disturbed and there were also no clear signs of exhaustion of the activity in the islets. Probably, biosynthesis of insulin is coming off only more quickly and is inducing a reduction of insulin already in the cell itself (according to the increased occurrence of lysosomes). The changed production of insulin which can be detected biochemically is, in some conditions, resulting from a temporally disturbance of the mechanism of secretion in the B-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.

The verification of neurones in the pancreas of spiny mice (Acomys cahirinus).

The statement that up to now no neural elements could be identified in the islets of Langerhans with the aid of electron microscopy led us to reinvestigate this question of innervation of the pancreas in spiny mice using light microscopy. Single nerve cells as well as nerve fibre bundles could be found in the interlobular connective tissue of the pancreas. By constrast, we could observe neither nerve cells nor nerve fibres in the islets of Langerhans. Extrainsular neuroinsular complexes could not be found either.

Electronmicroscopy studies on the exocrine pancreas of Wistar-Rats following treatment with Streptozotocin. / Elektronenmikroskopische Untersuchungen am exokrinen Pankreas von Wistar-Ratten nach Behandlung mit Streptozotocin

In Wistar rats the intraveneous injection of streptozotocin (65 mg/kg body weight) caused a permanent hyperglycemia. After 5 days there were lesions in the exocrine parenchyme of the pancreas and its nerve fibers. Pathological changes were found in cytoplasm, cell membrane, nucleus and all other cell organelles, too. The zymogen granules remaining after extensive degranulation may disintegrate in two different ways: 1. Shrinking of the granules and formation of a hale between granule membrane and core, the electronic density of which is decreased; indistinct demonstrability of the granule membrane and finally its decomposition. 2. Shrinking of the granules, decrease of the electron density and either homogeneous or mainly peripheral arrangement of the disintegrated material of the granules; irregular shape of the granules and splitting of their membranes.

[Methods of the histochemical detection of biogenic amines (author's transl)]. / Histochemische Nachweismethoden für biogene amine

Histochemical and ultrahistochemical methods for the demonstration of biogenic amines are investigated with regard to their efficiencies and limitations. For the purposes of the light microscopy fluorescent histochemical methods at present are sufficient. Hereby beta-arylethyl-amines and indolalkylamines are demonstrable with formaldehyde or glyoxylic acid whilst histamine is traceable with o-phthaldialdehyde. In this connection those chemical and physical conditions of this methods are shown, under which the demarcation and quantitative determination of the several amines is possible. Ultrahistochemically biogenic amines can be demonstrated by means of the chromaffine and the argentaffine reaction, the reaction with permanganate and the REINECKE-salt precipitation technique. Apart from the latter one, all these methods are based on an initially reaction between glutaraldehyde and amines. Thus these techniques might be founded on one and the same principle. Besides, the demonstration of adreanline as a secondary amine might be hindered also by the fact that the product of its reaction with glutaraldehyde is soluble in water. On the other hand the reaction product of primary amines with glutaraldehyde is insoluble in water. When using REINECKE-salt the correctly localizated precipitation of amines is the first step of the reaction. After that the treatment with glutaraldehyde is only serving for the fixation of the tissues. But the ultrahistochemical methods mentioned above altogether are showing a deficiency as far as they do not allow to make the several amines selectively visible. Therefore a quantitative ultrahistochemistry of biogenic amines is still impossible at present.

[The evidence of biogenic amines with Reinecke-salt as a new principle of evidence of substances in the ultrahistochemistry (author's transl)]. / Der Nachweis von biogenen Aminen mit Reinecke-Salz als ein neues Prinzip des Substanznachweises in der Ultrahistochemie

Reinecke-salt (ammonium tetracyanato diamine chromate) is known as amine precipitating reagens in applied chemistry. Its amine precipitates can be demonstrated in electron micrographes. The amine reineckates are unable to diffuse and difficult to dissolve. Depending from that they are localized in the cells. From our findings received in the boundary layer between adrenal cortex and adrenal medulla, we conclude that there are no non-specific precipitations with other cell components caused by Reinecke-salt. It could be determined that the catecholamines are accumulated in the cells of the adrenal medulla in granular shape in a typical manner. In the adrenal medulla cells of Acomys cahirinus first investigated by us we found amine containing vesicles with a diameter of 200 to 250 nm. In the neighbouring cells of the adrenal cortex no precipitates were visable. In the adrenal cortex we noticed the mitochondria from the tubulus typ specific for this region. The assumption that Reinecke-salt is a specific amine precipitating substance able of forming localized amin precipitates was confirmed by these investigations. So the Reineck-salt precipitation of biogenic amines is a new method beside the known ones for the ultrahistochemical amine demonstration. In our method the precipitation of amines by Reinecke-salt is the first step followed later by the tissue fixation with glutaraldehyde.

[The innervation of the thyroid gland of the sand rat (Psammomys obesus)]. / Zur Innervation der Glandula thyreoidea der Sandratte (Psammomys obesus)

It has been reported on the occurence of vegetative neurons in the stroma of the sand rat (Psammomys obesus) thyroid gland. The cells show all the typical signs of autonomic nerve cells. In contrast to neurons appearing in the pancreas of the sand rat, the neurons in the thyroid gland occur in most cases as singular neurons. The importance of the sympathetic innervation for the thyroid function has been discussed and the close relationship between thyroid hormone secretion and biogenic amines localized in the thyroid mast cells has been described as well.

[Electron microscope detection of biogenic amines in the medulla of the adrenal gland of the normoglycemic spiny mouse (Acomys cahirinus)]. / Elektronenmikroskopischer Nachweis von biogenen Aminen im Nebennierenmark der normoglykämischen Stachelmaus (Acomys cahirinus)

By means of a modification of the Reinecke salt method already described, characteristical amine containing granules have been demonstrated in the parenchymal cells of the adrenal medulla in normoglycemic spiny mice. By this method two types of granules have been discerned according to their different contrasts. The advantages of the modification method are discussed.