Identification of cell types containing S-100b protein-like immunoreactivity in the islets of Langerhans of the guinea pig pancreas with light and electron microscopy

Summary Cell types containing S-100b protein-like immunoreactivity in the islets of Langerhans of the guinea pig were studied by light- and electron-microscopic immunocytochemistry using antisera to S-100b protein, insulin, glicentin, somatostatin, and pancreatic polypeptide. Two types of S-100b-immunoreactive cells were identified. The first type was stellate and characterized by thin cytoplasmic processes sheathing endocrine-type cells, especially pancreatic A-cells. It was located predominantly in the neuro-insular complex and in large islets, both of which were located near the main pancreatic duct. Intense immunoreactivity was found in the cytoplasmic matrix as well as in the nucleoplasm. Nerve fibers or endings were occasionally ensheathed by its cytoplasmic processes. The second type, whose immunoreactivity was rather weak and varied from one cell to another, was oval to polygonal in shape and located randomly throughout the islets. It was an endocrine cell-type and its immunoreactivity was located in the secretory granule. With the use of immunostained consecutive sections for demonstrating pancreatic endocrine cell-types, it was found that a portion of the pancreatic B-cell population expressed S-100b-like immunoreactivity.     

Immunocytochemical localization of S-100 protein in stellate cells (folliculo-stellate cells) of the adenohypophysis in the monkeys Macaca irus and Cercopithecus aethiops

Summary With the use of an antibody against bovine S-100 protein, it was possible to reveal a characteristic cell type in the pars distalis and the pars tuberalis of the monkey Macaca irus. In the adenohypophysis of Cercopithecus aethiops, labeled cells were present in the pars distalis, pars tuberalis, and pars intermedia. These cells, so-called folliculo-stellate cells, were found in all pituitaries studied. Surprisingly, an antibody against human S-100 protein did not label the stellate cells of the adenohypophysis. However, in Macaca irus, this antibody gave a strong positive reaction with various other cell types (interstitial cells of the pineal gland, Müller cells of the retina, autonomic ganglionic cells, glial cells of the central nervous system, Schwann cells, Bergmann glia of the cerebellum, fat cells, reticular cells of lymphoid organs). By use of double immunoenzymatic labeling, it was evident that stellate cells are spatially related either to somatotropes, prolactin cells, corticotropes, or to glycoprotein-containing cells. Thus, a specific relationship to a particular endocrine-cell type could not be observed.Dr. M.P. Dubois died in Tours (France) on March 30, 1986, aged 65     

Immunohistochemical study of the pars tuberalis of the adenohypophysis in the monkey,Macaca irus

Summary The pars tuberalis of the hypophysis in the monkey Macaca irus encompasses the hypophysial stem up to the median eminence. Histologically, it consists of several layers of chromophobic cells. A few PAS¹-positive cells also stainable with Alcian blue (pH 3.0) can be observed among the unstained elements. Using the indirect immunofluorescence antibody technique, scattered immunoreactive cells were revealed with the anti-oLH antibody; these cells did not react with the anti-hFSH antibody. In contrast, the immunoreactions to anti-hGH, anti-hPRL, anti-ACTH, anti-MSH, anti-LPH and anti-endorphin sera were completely negative. Single cells reacting with the anti-hTSH serum were observed at the inferior end of the hypophysial stalk (zona tuberalis), i.e., beyond the pars tuberalis proper. These results are compared with data reported in the literature.

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Résumé La pars tuberalis de l'hypophyse du Singe Macacus irus entoure la tige infundibulaire jusqu'à l'éminence médiane. En techniques histologiques, elle apparaît constituée de plusieurs assises cellulaires d'aspect chromophobe. On y observe quelques cellules PAS-positives réagissant simultanément avec le bleu Alcian (pH3.0). En technique d'immunofluorescence indirecte, des cellules dispersées sont mises en évidence uniquement avec un anticorps anti-oLH; ces cellules ne réagissent pas avec un anticorps anti-hFSH. L'utilisation d'anticorps anti-hGH, anti-hPRL, anti-ACTH, anti-MSH, anti-LPH et antiendorphines ne permet pas de révéler des cellules immunoréactives. Quelques cellules réagissant avec un anticorps anti-hTSH s'observent à la base de la tige hypophysaire (zona tuberalis), c'est-à-dire au-delà de la pars tuberalis proprement dite. Ces résultats sont confrontés à ceux rapportés dans la littérature.

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Abbreviations used in this Article PAS periodic acid Schiff - oLH ovine luteinizing hormone - hFSH human follicle stimulating hormone - hGH human growth hormone - hPRL human prolactin - ACTH corticotropin - MSH melanotropin - LPH lipotropin - hTSH human thyrotropin - BSA and HSA bovine and human serum albumin     

CRF-immunoreactive nerve fibers in the circumventricular organs of the monkey,Macaca fuscata

Summary The occurrence of CRF (corticotropin-releasing factor)-immunoreactive nerve fibers in the circumventricular organs of adult male monkeys, Macaca fuscata, was studied on serially sectioned brains, by means of the peroxidase-antiperoxidase technique in combination with a highly specific and sensitive CRF antiserum. CRF-containing nerve fibers were found in high concentrations in the infundibulum and, in addition, in small numbers in the posterior lobe, organum vasculosum laminae terminalis, subfornical organ, and area postrema; they were missing in the pineal body and the subcommissural organ. The CRF immunoreactive nerve fibers distributed in these organs were located in the proximity of the blood vessels.Supported by a grant (No. 56440022) from the Ministry of Education, Science, and Culture, Japan     

Immunohistochemical demonstration of serotonin-containing nerve fibers in the hypothalamus of the monkey,Macaca fuscata

Summary The distributional pattern of serotonin-containing nerve fibers in the hypothalamus of the monkey (Macaca fuscata) was analyzed with the use of the peroxidaseantiperoxidase method in conjunction with a highly sensitive and specific anti-serotonin serum. The highest concentrations of serotonin-immunoreactive varicose fibers were found in the nucleus praeopticus medialis, nucleus ventromedialis hypothalami, and the complex of mammillary nuclei (nucleus praemamillaris, supramamillaris, mamillaris medialis et lateralis). However, the nucleus suprachiasmaticus, where numerous serotoninergic fibers have been reported to occur in the rat, appeared to be almost devoid of these fibers. The infundibular stalk, and the intermediate and posterior lobes of the pituitary contained considerable numbers of immunoreactive fibers. The present study provides a morphological basis for possible clarification of the influence of serotoninergic projections on various neuroendocrine mechanisms in primates. Furthermore, an attempt was made to clarify the differences and similarities concerning the distributional patterns of serotoninergic nerve fibers within the monkey hypothalamus in contrast to the rat hypothalamus.Supported by grants (No. 56440022, 57214028) from the Ministry of Education, Science and Culture, Japan     

Neuron-specific enolase,neurofilament protein and S-100 protein in the olfactory mucosa of human fetuses

Summary Immunohistochemical examination for neuronspecific enolase (NSE), neurofilament protein (NFP), and S-100 protein was performed in the olfactory mucosa of human fetuses. NSE and NFP immunoreactivities were found in the olfactory receptor cells, while no S-100 immunoreactive cells were recognized within the olfactory epithelium. The anti-NSE serum stained various types of nerve bundles in the lamina propria mucosae; a population of the NSE-positive nerve bundles was also immunoreactive for NFP. The anti-S-100 serum clearly demonstrated Schwann cells associated with the nerve fibers in the lamina propria mucosae. These findings 1) suggest a possibility of NSE and NFP as new marker substances for olfactory cells and 2) indicate that immunohistochemistry is a useful tool to analyse the cellular components of the olfactory organs in normal and pathological conditions.     

Immunocytochemical localization of S-100 protein in the hypophysis and saccus vasculosus of the elasmobranchs Mustelus manazo and Scyliorhinus torazame

Summary S-100 protein-immunoreactive cells were demonstrated by immunocytochemical procedures in the hypophysis and saccus vasculosus of two species of elasmobranchs (Mustelus manazo and Scyliorhinus torazame). In the saccus vasculosus of M. manazo, immunoreactivity was detectable exclusively in the fibrous portions interposed between the epithelial layer and the blood vessels. In the neurohypophysis, tanycytes and astrocytes of the median eminence were immunostained, but only a few labeled cells were found in the neurointermediate lobe. In S. torazame, the neurohypophysis displayed a similar distribution of immunoreactivity, but there were no labeled cells in the saccus vasculosus. In both species, none of the glandular cells of the hypophysis displayed immunoreactivity. Electron-microscopic examination showed that the immunostained cells in the saccus vasculosus correspond to astrocytes.     

Characteristic pattern of monoaminergic nerve fibers in the pineal organ of the monkey,Macaca fuscata

Summary Monoaminergic nerve fibers were studied in the pineal organ of the monkey, Macaca fuscata, by use of fluorescence and immunohistochemical procedures. Abundant formations of noradrenergic nerve fibers were observed in the pineal organ. They entered the parenchyma in the form of several coarse bundles via the capsule in the distal portion of the organ and spread throughout the organ after branching into smaller units. The density of the autonomic innervation decreased gradually toward the proximal portion of the organ. In the distal portion, numerous nerve fibers formed perivascular plexuses around the blood vessels and some fibers ran as bundles unrelated to the blood vessels in the stroma. Fine varicose fibers and bundles derived from these plexuses penetrated among the pinealocytes. However, only a few intraparenchymal fluorescent fibers were detected in the proximal third of the gland. With the use of serotonin antiserum serotonin-immunoreactive nerve fibers were clearly restricted to the ventroproximal part of the pineal organ. Although the somata of the pinealocytes showed intense immunoreactivity, their processes were not stained. In one exceptional case, clusters of pinealocytes displaying very intense immunoreactivity were found in an area extending from the distal margin of the ventral portion of the pineal stalk to the proximal portion of the pineal organ proper; these cells were bipolar or multipolar and endowed with well-stained processes.     

Microangioarchitecture of the islets of Langerhans in the snakes,Naja naja,Vipera russelli,andEchis carinatus

Summary Due to a decided lack in the literature of reports on the microangioarchitecture of the pancreas of snakes, an analysis was performed in three different species of two different ophidian families with the use of cast preparations and complementary scanning electron microscopy. The vascular architecture reflects the lobular substructure of the pancreas; the organ is supplied by branches of the superior mesentric artery. Coiled lobular arteries and arterioles continue into a meshwork of capillaries. Dilated capillaries of the endocrine portion of the pancreas are an integral component of this fine capillary network. A few very small capillaries establish a connection between the endocrine and the exocrine pancreas. The other capillaries drain into venules, which ultimately join their respective veins. No interspecific differences were noted in the vascularization of the pancreas of the three ophidian species examined. The present results suggest the existence of arterio-venous anastomoses and speak against the presence of a portal system, but establish a feed-forward capillary connection from the endocrine to the exocrine component of the ophidian pancreas.     

Localisation of substance P-like immunoreactivity in the ciliary ganglia of monkey (Macaca fascicularis) and cat: a light- and electron-microscopic study

The present study describes substance P-like immunoreactivity in the ciliary ganglia of monkey (Macaca fascicularis) and cat. About 60% of neurons in the monkey ciliary ganglion and 40% in the cat ciliary ganglion were substance P-like immunoreactive, ranging from faint to moderate staining. Substance P-like immunoreactivity was located in cell bodies, dendritic profiles and axons. In the monkey, substance P-like immunoreactive pericellular arborisations were associated with about 0.5%–3% of the ganglion cells, which were either negatively, faintly or moderately stained. An electron-microscopic study demonstrated the presence of either substance P-like immunoreactive positive or negative axon terminals synapsing or closely associated with positive dendritic profiles in both the monkey and cat ciliary ganglia. The results suggest that substance P plays an important role in the ciliary ganglion, perhaps as a modulator or transmitter.     

Filiform papillae as a sensory apparatus in the tongue: An immunohistochemical study of nervous elements by use of neurofilamcnt protein (NFP) and S-100 protein antibodies

Summary Nervous elements supplying the filiform papillae of the tongue of cattle and rats were investigated using immunohistochemistry against neurofilament protein (NFP) and glia-specific S-100 protein. The rod-shaped bovine filiform papillae were heavily keratinized along their entire length and lacked the connective tissue core that occurs in other mammals. Instead, the core was located posterior to the filiform papilla. The base of the bovine filiform papillae was invaded vertically by laminar connective tissue papillae. The core contained a large number of NFP-positive nerve fibers, most of them terminating as free endings in its anterior margin. NFP-positive nerves gathered around the anterior ridge of the epithelium at the base of the core and occasionally penetrated into the epithelium. The laminar connective tissue papillae at the base of the filiform papilla also contained NFP-positive nerve fibers. The core contained S-100-immunoreactive lamellated corpuscles, which were identified as simple corpuscles in electron micrographs. The structure and innervation of the bovine filiform papilla suggest that they represent a specialized sensory apparatus. The pyramidal filiform papillae of the rat were smaller, each containing a simple connective tissue core. Few NFP-positive nerve fibers from the nerve plexus entered the core. Filiform papillae are thus less specialized in rats than in cattle.     

Modulation of ATPase activities in the central nervous system by the S-100 proteins

The isomeric forms of bovine S-100a and S-100b have been shown to stimulate ATPase activities in fractions enriched in myelin and mitochondria isolated from the Gerbil brain and for S-100b more effectively than for calmodulin in erythrocytes or skeletal muscle. In the presence of Ca²⁺, S-100a produced a slight increase of ATPase activity in the mitochondrial fraction. However, S-100b, with or without Ca²⁺ and Zn²⁺ respectively, had no effect on the ATPase activity in mitochondria of the Gerbil liver. The observations may indicate a second messenger role for S-100b in the presence of Zn²⁺ in the Schwann cell.     

Distributional pattern of serotonin-immunoreactive nerve fibers in the lateral geniculate nucleus of the rat,cat and monkey (Macaca fuscata)

Summary The distribution of serotonin-containing nerve fibers in the lateral geniculate nucleus (LGN) of the rat, cat, and monkey (Macaca fuscata) was studied by use of the peroxidase-antiperoxidase method and an antiserum against serotonin. In all three species, the pattern of fibers was denser in the ventral portion of the LGN (LGNv) than in the dorsal nuclear portion (LGNd). In the LGNd of rat, serotonin-immunoreactive fibers were evenly distributed in the form of a dense network, but in cat and monkey there were marked regional differences. Serotonin-immunoreactive elements were most numerous in the C complex and medial interlaminal nucleus of cat, and in the S layer and interlaminar zones of Macaca fuscata.Supported by a grant from the Ministry of Education, Science, and Culture of Japan (No. 57214028)     

Principal cell types in the pancreatic islet of a teleost fish,Xiphophorus helleri H.

Summary By means of correlative light and electron microscopy, five pancreatic islet cell categories are described in the teleost fish, Xiphophorus helleri, each of which has specific light microscopic appearance and fine structure. Different histochemical techniques have been used, including immunofluorescence with antiporcine insulin and glucagon sera. In addition to B- and A₁-cells, two categories of A₂-cells have been observed, both reacting with antiporcine glucagon serum: A₂-cells with round granules gave a positive reaction for tryptophan; A₂-cells with crystalline granules gave a negative reaction with the same staining technique on the same section. The clear cells, the last category, were not specifically stained by any of the staining methods carried out in this investigation. The influence of fixation on staining affinities and on ultrastructure was shown to be considerable.Supported in part by the Deutsche Forschungsgemeinschaft, Bonn-Bad Godesberg (grant La 229/4) and by the Deutscher Akademischer Austauschdienst, Bonn-Bad Godesberg.     

Arginase expression and modulation of IL-1β-induced nitric oxide generation in rat and human islets of Langerhans

Proinflammatory cytokine induction of NO synthesis may contribute to the destruction of pancreatic beta cells leading to type 1 diabetes. The NO synthase substrate arginine can also be metabolized to ornithine and urea in a reaction catalyzed by cytosolic (AI) or mitochondrial (AII) isoforms of arginase. Recent evidence suggests that the rate of NO generation is dependent on the relative activities of NO synthase and arginase. The objectives of this study were (i) to identify the arginase isoforms expressed in rat and human islets of Langerhans and a rat beta cell line, RINm5F and (ii) to investigate the competition for arginine between NO synthase and arginase in IL-1β-treated rat islets. Arginase activity was detected in rat islets (fresh tissue, 346 mU/mg protein; cultured, 587 mU/mg), cultured human islets (56 mU/mg), RINm5F cells (376 mU/mg), rat kidney (238 mU/mg), and rat liver (6119 mU/mg). Using Western blots, AI was shown to be the predominant isoform expressed in rat islets and in RINm5F cells while human islets expressed far more AII than AI. Rat islets were cultured in medium containing 1.14, 0.1, and 0.01 mM arginine and treated with IL-1β and the arginase inhibitor 2(S)-amino-6-boronohexanoic acid (ABH). IL-1β-induced NO generation was unaffected by ABH at 1.14 mM arginine, but significantly increased at 0.1 and 0.01 mM arginine. These findings suggest that the level of islet arginase activity can regulate the rate of induced NO generation and this may be relevant to the insulitis process leading to beta cell destruction in type 1 diabetes.     

Hb Izu (Macaca)β83 (EF 7) Gly→Cys: The major hemoglobin of the Japanese monkey (Macaca fuscata) in a troop at Shimokita,the northernmost limit of its habitat

A hemoglobin variant was discovered in Japanese monkeys (Macaca fuscata) of the Wakinosawa A-1 troop of the Shimokita peninsula, the northernmost limit of this species' habitat. The variant was characterized by slow migration on starch gel electrophoresis due to its polymerizing nature. Structural analysis revealed that Gly at the 83rd amino acid residue of theβ chain was substituted by Cys, and the variant was identified as Hb Izu (Macaca). The gene frequency of the variant was extremely high, at 85.7%, and much higher than the 21.3% obtained for the troops of the Izu peninsula. The genotypic frequencies in the troops of both the Izu and Shimokita peninsulas agreed with expectations as calculated from the Hardy-Weinberg equilibrium.     

Distribution of opioidergic,sympathetic and neuropeptide Y-positive nerves in the sphincter of Oddi and biliary tree of the monkey,Macaca fascicularis

Summary The opioidergic, sympathetic and neuropeptide Y-positive innervation of the sphincter of Oddi (common bile duct sphincter and pancreatic duct sphincter), as well as other segments of the extrahepatic biliary tree was studied in the monkey by use of immunohistochemistry. Methionine-enkephalin-positive nerves were seen to innervate the smooth muscle of all portions of the sphincter of Oddi and also local ganglion cells. No methionine-enkephalin-positive nerves could be detected in the common bile duct, pancreatic duct or gallbladder. Tyrosine hydroxylase-positive nerves occurred between smooth muscle bundles and also ran to local ganglion cells as well as along the common bile duct. Neuropeptide Y-positive nerves were observed within smooth muscle of the sphincter of Oddi (all portions), common bile duct, pancreatic duct and gallbladder. No evidence of any differential innervation of the pancreatic duct and common bile duct sphincters could be detected with these markers.     

Detection of calcitonin gene expression in human infant and monkey carotid body chief cells by in situ hybridization

Calcitonin mRNA was detected in human and monkey carotid bodies by in situ hybridization histochemistry, using a ³⁵S-labeled oligonucleotide probe for human calcitonin. In both human and monkey carotid body, moderate to high hybridization signal for calcitonin mRNA was observed in all cases. The hybridization signal in the formalin-fixed, paraffin-embedded samples was comparable to that obtained from frozen paraformaldehyde-fixed tissue. Our observations extend the finding of calcitonin-like immunoreactivity in the carotid body chief cells and indicate that calcitonin is produced in the carotid body, probably in the chief cells.     

Dynamic localization of protein phosphatase type 1 in the mitotic cell cycle of Saccharomyces cerevisiae

Protein phosphatase type I (PP1), encoded by the single essential gene GLC7 in Saccharomyces cerevisiae, functions in diverse cellular processes. To identify in vivo subcellular location(s) where these processes take place, we used a functional green fluorescent protein (GFP)-Glc7p fusion protein. Time-lapse fluorescence microscopy revealed GFP-Glc7p localizes predominantly in the nucleus throughout the mitotic cell cycle, with the highest concentrations in the nucleolus. GFP-Glc7p was also observed in a ring at the bud neck, which was dependent upon functional septins. Supporting a role for Glc7p in bud site selection, a glc7-129 mutant displayed a random budding pattern. In alpha-factor treated cells, GFP-Glc7p was located at the base of mating projections, again in a septin-dependent manner. At the start of anaphase, GFP-Glc7p accumulated at the spindle pole bodies and remained there until cytokinesis. After anaphase, GFP-Glc7p became concentrated in a ring that colocalized with the actomyosin ring. A GFP-Glc7-129 fusion was defective in localizing to the bud neck and SPBs. Together, these results identify sites of Glc7p function and suggest Glc7p activity is regulated through dynamic changes in its location.