Peptide Hormones, Cytosolic Calcium and Renal Epithelial Response

1989 ◽  
pp. 149-166 ◽  
Author(s):  
Aubrey R. Morrison ◽  
Didier Portilla ◽  
Daniel Coyne
Keyword(s):  
Peptide Hormones ◽  
Cytosolic Calcium

Effect of verapamil on cytoplasmic distribution of granules and microfilaments in amphibian urinary bladder

1988 ◽  
Vol 46 ◽  
pp. 324-325
Author(s):  
A.J. Mia ◽  
L.X. Oakford ◽  
T. Yorio
Keyword(s):  
Urinary Bladder ◽  
Water Flow ◽  
Morphological Changes ◽  
Granular Cell ◽  
Cytosolic Calcium ◽  
Calcium Storage ◽  
Amphibian Urinary Bladder ◽  
Vesicular Membrane ◽  
High Concentrations ◽  
Cytoskeletal System

The amphibian urinary bladder has been used as a ‘model’ system for studies of the mechanism of action of antidiuretic hormone (ADH) in stimulating transepithelial water flow. The increase in water permeability is accompanied by morphological changes that include the stimulation of apical microvilli, mobilization of microtubules and microfilaments and vesicular membrane fusion events . It has been shown that alterations in the cytosolic calcium concentrations can inhibit ADH transmembrane water flow and induce alterations in the epithelial cell cytomorphology, including the cytoskeletal system . Recently, the subapical granules of the granular cell in the amphibian urinary bladder have been shown to contain high concentrations of calcium, and it was suggested that these cytoplasmic constituents may act as calcium storage sites for intracellular calcium homeostasis. The present study utilizes the calcium antagonist, verapamil, to examine the effect of calcium deprivation on the cytomorphological features of epithelial cells from amphibian urinary bladder, with particular emphasis on subapical granule and microfilament distribution.

Plant peptide hormone signalling

2015 ◽  
Vol 58 ◽  
pp. 115-131 ◽  
Author(s):  
Ayane Motomitsu ◽  
Shinichiro Sawa ◽  
Takashi Ishida
Keyword(s):  
Communication Systems ◽  
Cell Communication ◽  
Peptide Hormone ◽  
Peptide Hormones ◽  
Target Cells ◽  
Signalling Molecules ◽  
Receptor Complexes ◽  
Environmental Responses ◽  
Plant Life Cycle ◽  
Multicellular Organisms

The ligand–receptor-based cell-to-cell communication system is one of the most important molecular bases for the establishment of complex multicellular organisms. Plants have evolved highly complex intercellular communication systems. Historical studies have identified several molecules, designated phytohormones, that function in these processes. Recent advances in molecular biological analyses have identified phytohormone receptors and signalling mediators, and have led to the discovery of numerous peptide-based signalling molecules. Subsequent analyses have revealed the involvement in and contribution of these peptides to multiple aspects of the plant life cycle, including development and environmental responses, similar to the functions of canonical phytohormones. On the basis of this knowledge, the view that these peptide hormones are pivotal regulators in plants is becoming increasingly accepted. Peptide hormones are transcribed from the genome and translated into peptides. However, these peptides generally undergo further post-translational modifications to enable them to exert their function. Peptide hormones are expressed in and secreted from specific cells or tissues. Apoplastic peptides are perceived by specialized receptors that are located at the surface of target cells. Peptide hormone–receptor complexes activate intracellular signalling through downstream molecules, including kinases and transcription factors, which then trigger cellular events. In this chapter we provide a comprehensive summary of the biological functions of peptide hormones, focusing on how they mature and the ways in which they modulate plant functions.

A rhythm in the flowering response of photoperiodically-induced Pharbitis nil to agents affecting cytosolic calcium and pH

1992 ◽  
Vol 85 (1) ◽  
pp. 57-60 ◽  
Author(s):  
Haya Friedman ◽  
Eliezer E. Goldschmidt ◽  
Hanna Spiegelstein ◽  
Abraham H. Halevy
Keyword(s):  
Cytosolic Calcium ◽  
Pharbitis Nil ◽  
Flowering Response

Immunoglobulins G are precursors of peculiar peptide hormones

1997 ◽  
Vol 56 (1-3) ◽  
pp. 399
Author(s):  
V Abramov
Keyword(s):  
Peptide Hormones

Hypersensitivity to Thromboxane A2 in Cholesterol-Rich Human Platelets

1990 ◽  
Vol 64 (04) ◽  
pp. 594-599 ◽  
Author(s):  
Takuya Tomizuka ◽  
Kyohei Yamamoto ◽  
Aizan Hirai ◽  
Yasushi Tamura ◽  
Sho Yoshida
Keyword(s):  
Calcium Concentration ◽  
Binding Capacity ◽  
Thromboxane A2 ◽  
Cytosolic Calcium ◽  
Cholesterol Content ◽  
Human Platelets ◽  
Dissociation Rate ◽  
Platelet Membrane ◽  
Maximal Concentration ◽  
Equilibrium Dissociation

SummaryThe effect of changes in platelet membrane cholesterol content on thromboxane A2 (TXA2)-induced platelet activation was studied. Concentrations of 9,ll-epithio-ll,12-methano-TXA2 (STA2), a stable analogue of TXA2 which can cause half-maximal aggregation and release of [14C]serotonin in cholesterol-rich platelets were significantly lower than those in cholesterol-normal platelets. STA2-induced increase in cytosolic calcium concentration and [32P]phosphatidic acid formation in cholesterol-rich platelets were significantly greater than those in cholesterol-normal platelets. The maximal concentration of binding site (Bmax) for SQ29548 was significantly increased in cholesterol-rich platelets compared with cholesterol-normal platelets, while the equilibrium dissociation rate constant (Kd) for SQ29548 did not differ between cholesterol-rich and cholesterol-normal platelets. The present study suggested that sensitivity to TXA2 was increased by the incorporation of cholesterol into platelet membrane and that the cause of hypersensitivity to TXA2 in cholesterol-rich platelets may be partly explained by an increase in binding capacity for TXA2.

INHIBITION OF LIPOLYTIC ACTIVITY OF SYNTHETIC β1–24 AND β1–39 CORTICOTROPHIN BY ANTI-ACTH ANTISERUM

1966 ◽  
Vol 51 (1) ◽  
pp. 88-94 ◽  
Author(s):  
A. Villanueva ◽  
S. J. H. Ashcroft ◽  
J. P. Felber
Keyword(s):  
Guinea Pig ◽  
Lipolytic Activity ◽  
Peptide Hormones ◽  
Fat Pad ◽  
Double Antibody ◽  
Epididymal Fat ◽  
Antibody Complex ◽  
Radio Immunoassay ◽  
Antigen Antibody

ABSTRACT The synthetic ACTH peptides β1–39 and β1–24 stimulated lipolysis as determined by the rat epididymal fat pad in vitro. The stimulating effect of these peptides was diminished by prior incubation of the peptides with antibodies produced by the guinea-pig against ACTH. The stimulating effect of these hormones was also diminished by the double antibody system used in the radio-immunoassay of ACTH and other peptide hormones, in which incubation with antiserum is followed by precipitation of the antigen-antibody complex by rabbit anti-guinea-pig-γ-globulin.

Transport of peptide hormones across isolated rat mesentery: effect of human serum-bound insulin

Diabetes ◽  
1975 ◽  
Vol 24 (11) ◽  
pp. 997-1004 ◽  
Author(s):  
J. D. Simon ◽  
H. N. Antoniades
Keyword(s):  
Human Serum ◽  
Peptide Hormones ◽  
Rat Mesentery ◽  
Isolated Rat
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