Endocrine regulation of prolactin cell function and modulation of osmoreception in the Mozambique tilapia

2013 ◽  
Vol 192 ◽  
pp. 191-203 ◽  
Author(s):  
A.P. Seale ◽  
Y. Yamaguchi ◽  
W.M. Johnstone ◽  
R.J. Borski ◽  
D.T. Lerner ◽  
...  
Keyword(s):  
Cell Function ◽  
Endocrine Regulation ◽  
Mozambique Tilapia ◽  
Prolactin Cell

scholarly journals The Role of the α Cell in the Pathogenesis of Diabetes: A World beyond the Mirror

2021 ◽  
Vol 22 (17) ◽  
pp. 9504
Author(s):  
María Sofía Martínez ◽  
Alexander Manzano ◽  
Luis Carlos Olivar ◽  
Manuel Nava ◽  
Juan Salazar ◽  
...  
Keyword(s):  
Cell Function ◽  
Cell Mass ◽  
Glucagon Secretion ◽  
Endocrine Regulation ◽  
Β Cell ◽  
Cell Hyperplasia ◽  
Dipeptidyl Peptidase 4 ◽  
Dipeptidyl Peptidase 4 Inhibitors ◽  
Glucagon Like Peptide 1 ◽  
Chronic Hyperglycaemia

Type 2 Diabetes Mellitus (T2DM) is one of the most prevalent chronic metabolic disorders, and insulin has been placed at the epicentre of its pathophysiological basis. However, the involvement of impaired alpha (α) cell function has been recognized as playing an essential role in several diseases, since hyperglucagonemia has been evidenced in both Type 1 and T2DM. This phenomenon has been attributed to intra-islet defects, like modifications in pancreatic α cell mass or dysfunction in glucagon’s secretion. Emerging evidence has shown that chronic hyperglycaemia provokes changes in the Langerhans’ islets cytoarchitecture, including α cell hyperplasia, pancreatic beta (β) cell dedifferentiation into glucagon-positive producing cells, and loss of paracrine and endocrine regulation due to β cell mass loss. Other abnormalities like α cell insulin resistance, sensor machinery dysfunction, or paradoxical ATP-sensitive potassium channels (KATP) opening have also been linked to glucagon hypersecretion. Recent clinical trials in phases 1 or 2 have shown new molecules with glucagon-antagonist properties with considerable effectiveness and acceptable safety profiles. Glucagon-like peptide-1 (GLP-1) agonists and Dipeptidyl Peptidase-4 inhibitors (DPP-4 inhibitors) have been shown to decrease glucagon secretion in T2DM, and their possible therapeutic role in T1DM means they are attractive as an insulin-adjuvant therapy.

Release of α-Subunit of Glycoprotein Hormones from the Bullfrog Pituitary: Possible Effect of α-Subunit on Prolactin Cell Function

1996 ◽  
Vol 102 (1) ◽  
pp. 141-146 ◽  
Author(s):  
Atsuko Oguchi ◽  
Shigeyasu Tanaka ◽  
Kazutoshi Yamamoto ◽  
Sakae Kikuyama
Keyword(s):  
Cell Function ◽  
Glycoprotein Hormones ◽  
Α Subunit ◽  
Prolactin Cell

Annexin 5: A possible regulating factor of pituitary prolactin cell function

1994 ◽  
Vol 1 ◽  
pp. 178
Author(s):  
M. Kawaminami ◽  
S. Kurusu ◽  
I. Hashimoto ◽  
A.M. Walker
Keyword(s):  
Cell Function ◽  
Prolactin Cell ◽  
Pituitary Prolactin

Freeze-substitution of rye grass and ragweed pollen grains

1990 ◽  
Vol 48 (3) ◽  
pp. 686-687
Author(s):  
Liza B. Martinez ◽  
Susan M. Wick
Keyword(s):  
Cell Function ◽  
Pollen Grains ◽  
Freeze Substitution ◽  
Cell Types ◽  
Rapid Freezing ◽  
Rye Grass ◽  
Acrylic Resins ◽  
Allergenic Proteins ◽  
Cold Embedding ◽  
Structural Preservation

Rapid freezing and freeze-substitution have been employed as alternatives to chemical fixation because of the improved structural preservation obtained in various cell types. This has been attributed to biomolecular immobilization derived from the extremely rapid arrest of cell function. These methods allow the elimination of conventionally used fixatives, which may have denaturing or “masking” effects on proteins. Thus, this makes them ideal techniques for immunocytochemistry, in which preservation of both ultrastructure and antigenicity are important. These procedures are also compatible with cold embedding acrylic resins which are known to increase sensitivity in immunolabelling.This study reveals how rapid freezing and freeze-substitution may prove to be useful in the study of the mobile allergenic proteins of rye grass and ragweed. Most studies have relied on the use of osmium tetroxide to achieve the necessary ultrastructural detail in pollen whereas those that omitted it have had to contend with poor overall preservation.

Confocal imaging of calcium in intact ventricular muscle provides a new view of excitation-contraction coupling

1996 ◽  
Vol 54 ◽  
pp. 738-739
Author(s):  
W.G. Wier
Keyword(s):  
Local Control ◽  
Cardiac Tissue ◽  
Cell Function ◽  
Isolated Heart ◽  
Cardiac Cells ◽  
Confocal Imaging ◽  
Ion Concentration ◽  
Heart Cell ◽  
Free Calcium ◽  
Heart Cells

A fundamentally new understanding of cardiac excitation-contraction (E-C) coupling is being developed from recent experimental work using confocal microscopy of single isolated heart cells. In particular, the transient change in intracellular free calcium ion concentration ([Ca2+]i transient) that activates muscle contraction is now viewed as resulting from the spatial and temporal summation of small (∼ 8 μm3), subcellular, stereotyped ‘local [Ca2+]i-transients' or, as they have been called, ‘calcium sparks'. This new understanding may be called ‘local control of E-C coupling'. The relevance to normal heart cell function of ‘local control, theory and the recent confocal data on spontaneous Ca2+ ‘sparks', and on electrically evoked local [Ca2+]i-transients has been unknown however, because the previous studies were all conducted on slack, internally perfused, single, enzymatically dissociated cardiac cells, at room temperature, usually with Cs+ replacing K+, and often in the presence of Ca2-channel blockers. The present work was undertaken to establish whether or not the concepts derived from these studies are in fact relevant to normal cardiac tissue under physiological conditions, by attempting to record local [Ca2+]i-transients, sparks (and Ca2+ waves) in intact, multi-cellular cardiac tissue.

Adipokines as key players in β cell function and failure

2019 ◽  
Vol 133 (22) ◽  
pp. 2317-2327 ◽  
Author(s):  
Nicolás Gómez-Banoy ◽  
James C. Lo
Keyword(s):  
Metabolic Diseases ◽  
Cell Function ◽  
Whole Body ◽  
Pancreatic Β Cell ◽  
Β Cell ◽  
Cell Axis ◽  
Β Cell Function ◽  
Prevalence Of Obesity ◽  
Specific Factors ◽  
Whole Body Metabolism

Abstract The growing prevalence of obesity and its related metabolic diseases, mainly Type 2 diabetes (T2D), has increased the interest in adipose tissue (AT) and its role as a principal metabolic orchestrator. Two decades of research have now shown that ATs act as an endocrine organ, secreting soluble factors termed adipocytokines or adipokines. These adipokines play crucial roles in whole-body metabolism with different mechanisms of action largely dependent on the tissue or cell type they are acting on. The pancreatic β cell, a key regulator of glucose metabolism due to its ability to produce and secrete insulin, has been identified as a target for several adipokines. This review will focus on how adipokines affect pancreatic β cell function and their impact on pancreatic β cell survival in disease contexts such as diabetes. Initially, the “classic” adipokines will be discussed, followed by novel secreted adipocyte-specific factors that show therapeutic promise in regulating the adipose–pancreatic β cell axis.

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