MORPHOLOGY OF ENDOCRINE CELLS IN THE ISLET TISSUE OF THE COD GADUS CALLARIAS

1970 ◽  
Vol 63 (4) ◽  
pp. 679-695 ◽  
Author(s):  
N. W. Thomas
Keyword(s):  
Endocrine Cells ◽  
Secretory Granules ◽  
Cell Types ◽  
Differential Staining ◽  
Cell Type ◽  
Central Mass ◽  
Islet Tissue ◽  
History Of ◽  
Alpha Beta ◽  
Delta Cells

ABSTRACT The principal islet of the cod consists of a central mass of endocrine tissue, surrounded by a capsule of exocrine tissue. Four cell types are recognisable by differential staining and electron microscopy. Three of these correspond in staining reactions and general morphology to alpha, beta and delta cells of other species. Each cell-type contains characteristic secretory granules. The fourth cell-type does not appear to correspond to any other pancreatic endocrine cell although its granules show features common to both alpha and beta cells. It may represent a phase in the life history of one of these cell types or more probably a separate cell-type.

The effect of pancreatic mesenchyme on the differentiation of endocrine cells from gastric endoderm

Development ◽  
1987 ◽  
Vol 100 (4) ◽  
pp. 661-671 ◽  
Author(s):  
B. Kramer ◽  
A. Andrew ◽  
B.B. Rawdon ◽  
P. Becker
Keyword(s):  
Endocrine Cell ◽  
Endocrine Cells ◽  
Cell Types ◽  
The Other ◽  
Chick Embryos ◽  
Cell Type ◽  
Pancreatic Insulin ◽  
Somatostatin Cells ◽  
Regional Specificity ◽  
Gut Endocrine Cells

To determine whether mesenchyme plays a part in the differentiation of gut endocrine cells, proventricular endoderm from 4- to 5-day chick or quail embryos was associated with mesenchyme from the dorsal pancreatic bud of chick embryos of the same age. The combinations were grown on the chorioallantoic membranes of host chick embryos until they reached a total incubation age of 21 days. Proventricular or pancreatic endoderm of the appropriate age and species reassociated with its own mesenchyme provided the controls. Morphogenesis in the experimental grafts corresponded closely to that in proventricular controls, i.e. the pancreatic mesenchyme supported the development of proventricular glands from proventricular endoderm. Insulin, glucagon and somatostatin cells and cells with pancreatic polypeptide-like immunoreactivity differentiated in the pancreatic controls. The latter three endocrine cell types, together with neurotensin and bombesin/gastrin-releasing polypeptide (GRP) cells, developed in proventricular controls and experimental grafts. The proportions of the major types common to proventriculus and pancreas (somatostatin and glucagon cells) were in general similar when experimental grafts were compared with proventricular controls but different when experimental and pancreatic control grafts were compared. Hence pancreatic mesenchyme did not materially affect the proportions of these three cell types in experimental grafts, induced no specific pancreatic (insulin) cell type and allowed the differentiation of the characteristic proventricular endocrine cell types, neurotensin and bombesin/GRP cells. However, an important finding was a significant reduction in the proportion of bombesin/GRP cells, attributable in part to a decrease in their number and in part to an increase in the numbers of endocrine cells of the other types. This indicates that mesenchyme may well play a part in determining the regional specificity of populations of gut endocrine cells.

Fine structure and immunocytochemistry of cells within the endocrine pancreas of the gar (Lepisosteus osseus)

1998 ◽  
Vol 76 (1) ◽  
pp. 6-18 ◽  
Author(s):  
Karen E Groff ◽  
John H Youson
Keyword(s):  
Endocrine Pancreas ◽  
Cell Types ◽  
Structural Features ◽  
Nerve Terminals ◽  
Cell Type ◽  
Similar Morphology ◽  
Islet Tissue ◽  
Ancient Lineage ◽  
D Cell ◽  
D Cells

Routine electron microscopy and immunocytochemistry were used to describe the cell types in the islets of the endocrine pancreas of the gar Lepisosteus osseus, an actinopterygian fish of the order Semionotiformes, which has an ancient lineage. The general fine-structural features of cells composing the islets reflect their synthesis and packaging of protein for liberation at their perivascular surface. Cells are directly apposed to numerous capillaries and they are richly innervated with nerve terminals containing dense-cored vesicles. The islet tissue comprises many B cells, which are easily distinguished by their ubiquitous granules with polymorphous matrix cores and a loose-fitting membrane. These granules are only immunoreactive with an insulin antiserum. Only one type of D cell is found throughout the islets and it contains many granules of varying electron density, the most abundant granule profile being dumbbell-shaped. All granules in this cell type have a tight-fitting limiting membrane and they immunostain with antisomatostatin-14 and -34. Cells at the periphery of the islet contained granules of similar morphology to those in the D cells, but the granules were less numerous. Many granules in the cells were immunoreactive with both antiglucagon and antineuropeptideY, while others immunostained with only one of these antibodies. Since no cells stained exclusively for either glucagon or neuropeptide Y, it was concluded that there are only three cell types in the endocrine pancreas of the gar: B and D cells and a third cell type (A/F) that co-localizes peptides of the glucagon and pancreatic polypeptide family. Although this co-localization is not uncommon in the vertebrate endocrine pancreas, it may have some phylogenetic and (or) ontogenetic significance in this organism.

scholarly journals Cell Type-Specific Metabolism of Peptidylglycineα -Amidating Monooxygenase in Anterior Pituitary*

Endocrinology ◽  
2000 ◽  
Vol 141 (8) ◽  
pp. 3020-3034 ◽  
Author(s):  
Rajaa El Meskini ◽  
Richard E. Mains ◽  
Betty A. Eipper
Keyword(s):  
Anterior Pituitary ◽  
Secretory Granules ◽  
Primary Cultures ◽  
Cell Types ◽  
Pituitary Cell ◽  
Male Rat ◽  
Pituitary Cells ◽  
Cell Type ◽  
Cell Content ◽  
Monooxygenase Activity

Peptidylglycine α-amidating monooxygenase (PAM) is a bifunctional enzyme expressed in each major anterior pituitary cell type. We used primary cultures of adult male rat anterior pituitary to examine PAM expression, processing, and secretion in the different pituitary cell types and to compare these patterns to those observed in transfected AtT-20 corticotrope tumor cells. Immunostaining and subcellular fractionation identified PAM in pituitary secretory granules and additional vesicular compartments; in contrast, in AtT-20 cells, transfected PAM was primarily localized to the trans-Golgi network. PAM expression was highest in gonadotropes, with moderate levels in somatotropes and thyrotropes and lower levels in corticotropes and lactotropes. Under basal conditions, less than 1% of the cell content of monooxygenase activity was secreted per h, a rate comparable to the basal rate of release of individual pituitary hormones. General secretagogues stimulated PAM secretion 3- to 5-fold. Stimulation with specific hypothalamic releasing hormones demonstrated that different pituitary cell types secrete characteristic sets of PAM proteins. Gonadotropes and thyrotropes release primarily monofunctional monooxygenase. Somatotropes secrete primarily bifunctional PAM, whereas corticotropes secrete a mixture of mono- and bifunctional proteins. As observed in transfected AtT-20 cells, pituitary cells rapidly internalize the PAM/PAM-antibody complex from the cell surface. The distinctly different steady-state localizations of endogenous PAM in primary pituitary cells and transfected PAM in AtT-20 cell lines may simply reflect the increased storage capacity of primary pituitary cells.

scholarly journals Chromatin accessibility differences between alpha, beta, and delta cells identifies common and cell type-specific enhancers

2021 ◽  
Author(s):  
Alex M. Mawla ◽  
Talitha van der Meulen ◽  
Mark O. Huising
Keyword(s):  
Beta Cells ◽  
Islet Cell ◽  
High Throughput Sequencing ◽  
Expression Patterns ◽  
Critical Role ◽  
Cell Types ◽  
Chromatin Accessibility ◽  
Alpha Beta ◽  
Cellular Identity ◽  
Delta Cells

AbstractHigh throughput sequencing has enabled the interrogation of the transcriptomic landscape of glucagon-secreting alpha cells, insulin-secreting beta cells, and somatostatin-secreting delta cells. These approaches have furthered our understanding of expression patterns that define healthy or diseased islet cell types and helped explicate some of the intricacies between major islet cell crosstalk and glucose regulation. All three endocrine cell types derive from a common pancreatic progenitor, yet alpha and beta cells have partially opposing functions, and delta cells modulate and control insulin and glucagon release. While gene signatures that define and maintain cellular identity have been widely explored, the underlying epigenetic components are incompletely characterized and understood. Chromatin accessibility and remodeling is a dynamic attribute that plays a critical role to determine and maintain cellular identity. Here, we compare and contrast the chromatin landscape between mouse alpha, beta, and delta cells using ATAC-Seq to evaluate the significant differences in chromatin accessibility. The similarities and differences in chromatin accessibility between these related islet endocrine cells help define their fate in support of their distinct functional roles. We identify patterns that suggest that both alpha and delta cells are poised, but repressed, from becoming beta-like. We also identify patterns in differentially enriched chromatin that have transcription factor motifs preferentially associated with different regions of the genome. Finally, we identify and visualize both novel and previously discovered common endocrine- and cell specific- enhancer regions across differentially enriched chromatin.

Categorization of Physiologically and Morphologically Characterized non-α/non-β Cat Retinal Ganglion Cells Using Fractal Geometry

Fractals ◽  
1997 ◽  
Vol 05 (04) ◽  
pp. 673-684 ◽  
Author(s):  
H. F. Jelinek ◽  
I. Spence
Keyword(s):  
Fractal Dimension ◽  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Cell Types ◽  
Retinal Ganglion ◽  
Cell Type ◽  
Box Counting ◽  
Standard Values ◽  
Box Counting Method ◽  
Delta Cells

Non-α/non-β cat retinal ganglion cell images were obtained from the published literature, and a homogeneous group of cells was chosen as a standard for each currently accepted cell type (γ, δ and ε). The NIH box-counting method was chosen to determine the fractal dimension (Df) of all cells. The 'standard' values allowed comparisons with other morphologically and physiologically non-α/non-β classified cell types in the literature. We suggest, based on fractal analysis of the dendritic trees, that the morphologically defined γ, δ, and ε cells are distinct types. The W-tonic and W-phasic cell types were further divided into 2 subcategories (W-tonic1, W-tonic2, W-phasic1, W-phasic2). The fractal dimension, of the ε cells being equivalent to the W-tonic1 group and γ cell type equivalent to the W-phasic1 group. Delta cells may be equivalent to either the W-tonic2 or the W-phasic2 group. We discuss the value of the fractal dimension as an added morphological parameter for future morphophysiological classification schemes of vertebrate retinal ganglion cells.

Morphological study of the gut in Sagitta setosa, S. serratodentata and S. pacifica (Chaetognatha). Functional implications in digestive processes

1999 ◽  
Vol 79 (6) ◽  
pp. 1097-1109 ◽  
Author(s):  
Y. Perez ◽  
J. Arnaud ◽  
M. Brunet ◽  
J.-P. Casanova ◽  
J. Mazza
Keyword(s):  
Intestinal Epithelium ◽  
Morphological Study ◽  
Secretory Cell ◽  
Secretory Granules ◽  
Ciliated Cell ◽  
Posterior Part ◽  
Cell Types ◽  
Cell Type ◽  
Distinct Cell ◽  
Functional Implications

The study of the digestive epithelium in Sagitta setosa, S. serratodentata, and S. pacifica revealed only a few morphological and cytological differences among the three species. The gut was divided in two main regions. The first is the cephalic region where the epithelium is composed of three distinct cell types (S1, S2, and S3), the ultrastructure of which is probably specialized either for the synthesis of mucosubstances (S1), or enzymes (S3), or both (S2). The second region of the gut extends to the trunk and is mainly composed of the intestine and a short vertical rectum. No intestinal diverticula were observed. The intestinal epithelium displayed two ciliated cell types, anteriorly, a secretory cell type (S4) containing large mucus-like granules, and a second cell type (A) predominated in the posterior part of the intestine. A-cells appear to have two main functions. Although they exhibit secretory granules, they also display typical endocytotic features in their upper half, i.e. coated vesicles, a well-developed tubulo–vesicular network and two distinct types of digestive vacuoles corresponding to an endosome–lysosome-like system. From the distribution and presumed function of the cells, the gut may be divided in two main functional units, i.e. the cephalic and trunk units.

Selective staining of secretory granules of adrenal medullary cells by silver methenamine: A light and electron microscopic study

1968 ◽  
Vol 46 (5) ◽  
pp. 745-747 ◽  
Author(s):  
William W. L. Chang ◽  
Sergio A. Bencosme
Keyword(s):  
Microscopic Study ◽  
Adrenal Medulla ◽  
Electron Microscopic Study ◽  
Secretory Granules ◽  
Cell Types ◽  
Cell Type ◽  
Glutaraldehyde Fixation ◽  
Electron Microscopic ◽  
Selective Staining ◽  
The Third

A reevaluation of the silver methenamine reaction as an electron stain has ensued from recent use of glutaraldehyde fixation alone. By this technique, three cell types of rat adrenal medulla were found: (i) the norepinephrine-containing cells showed selectively stained, irregular, black granules; (ii) the epinephrine-containing cells showed round, light-grey granules; and (iii) the third cell type showed round granules like those of epinephrine-containing cells, but black in color, similar to those of the norepinephrine-containing cells.

scholarly journals The larval midgut of Anticarsia gemmatalis (Hübner) (Lepidoptera: Noctuidae): light and electron microscopy studies of the epithelial cells

2004 ◽  
Vol 64 (3b) ◽  
pp. 633-638 ◽  
Author(s):  
S. M. Levy ◽  
A. M. F. Falleiros ◽  
E. A. Gregório ◽  
N. R. Arrebola ◽  
L. A. Toledo
Keyword(s):  
Electron Microscopy ◽  
Endocrine Cells ◽  
Secretory Granules ◽  
Light And Electron Microscopy ◽  
Cell Types ◽  
Anticarsia Gemmatalis ◽  
Epithelial Tissue ◽  
Basal Region ◽  
Transmission Electron ◽  
Basal Portion

The morphology of the midgut epithelium cells of Anticarsia gemmatalis (Hübner) larvae is described by light and transmission electron microscopy. The midgut of A. gemmatalis is the largest portion of the digestive tract, with three distinct regions: proximal, media and distal. Its wall is formed by pseudostratified columnar epithelial tissue having four cell types: columnar, goblet, regenerative, and endocrine cells. The columnar cells are numerous and long, with the apical portion showing many lengthy microvilli and the basal portion invaginations forming a basal labyrinth. The goblet cells have a large goblet-shaped central cavity delimited by cytoplasmic projections filled with mitochondria. The regenerative cells present electron-dense cytoplasm and few organelles. The endocrine cells are characterized by electron-dense secretory granules, usually concentrated in the cytoplasm basal region.

scholarly journals Ultrastructure of the midgut endocrine cells in Melipona quadrifasciata anthidioides (Hymenoptera, Apidae)

2003 ◽  
Vol 63 (4) ◽  
pp. 683-690 ◽  
Author(s):  
C. A. Neves ◽  
L. B. Gitirana ◽  
J. E. Serrão
Keyword(s):  
Golgi Complex ◽  
Endocrine Cells ◽  
Secretory Granules ◽  
Basal Area ◽  
Cell Type ◽  
Open Cell ◽  
Autophagic Vacuoles ◽  
Posterior Midgut ◽  
Closed Type ◽  
Secretion Granules

In this study we describe the ultrastructure of the endocrine cells observed in the midgut of M. quadrifasciata anthidioides. This bee has two types of endocrine cells, which are numerous on the posterior midgut region. Cells of the closed type are smaller and have irregular secretory granules with lower electrondensity than those of the open cell type. The open cell type has elongated mitochondria mainly on the basal area, where most of the secretory granules are also found. Besides the secretion granules and mitochondria, endocrine cells in this species have well-developed autophagic vacuoles and Golgi complex elements.

scholarly journals Cell type-dependent variations in the subcellular distribution of alpha-mannosidase I and II

1993 ◽  
Vol 122 (1) ◽  
pp. 39-51 ◽  
Author(s):  
A Velasco ◽  
L Hendricks ◽  
KW Moremen ◽  
DR Tulsiani ◽  
O Touster ◽  
...  
Keyword(s):  
Cell Surface ◽  
Secretory Granules ◽  
Acinar Cells ◽  
Cell Types ◽  
Goblet Cells ◽  
Cross Reactivity ◽  
Pancreatic Acinar Cells ◽  
Cell Type ◽  
Golgi Stack ◽  
Cell Surface Staining

alpha-mannosidases I and II (Man I and II) are resident enzymes of the Golgi complex involved in oligosaccharide processing during N-linked glycoprotein biosynthesis that are widely considered to be markers of the cis- and medial-Golgi compartments, respectively. We have investigated the distribution of these enzymes in several cell types by immunofluorescence and immunoelectron microscopy. Man II was most commonly found in medial- and/or trans- cisternae but showed cell type-dependent variations in intra-Golgi distribution. It was variously localized to either medial (NRK and CHO cells), both medial and trans (pancreatic acinar cells, enterocytes), or trans- (goblet cells) cisternae, or distributed across the entire Golgi stack (hepatocytes and some enterocytes). The distribution of Man I largely coincided with that of Man II in that it was detected primarily in medial- and trans-cisternae. It also showed cell type dependent variations in its intra-Golgi distribution. Man I and Man II were also detected within secretory granules and at the cell surface of some cell types (enterocytes, pancreatic acinar cells, goblet cells). In the case of Man II, cell surface staining was shown not to be due to antibody cross-reactivity with oligosaccharide epitopes. These results indicate that the distribution of Man I and Man II within the Golgi stack of a given cell type overlaps considerably, and their distribution from one cell type to another is more variable and less compartmentalized than previously assumed.

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