rho-kinase is an effector molecule of rhoa, a monomeric gtp-binding protein, and causes ca2+ sensitization through inactivation of myosin phosphatase. the major physiological functions of rho/rho-kinase cascade include contraction, proliferation and migration in cells.there are some excellent reviews about rho/rho-kinase signal pathway, most of which focus on the specific proteins of the pathwa...

ATP and UTP cause mobilization of Ca2+ from the intracellular stores with similar potency in several cell types including both undifferentiated and differentiated HL60 cells. We show here that, in HL60 cells with Ca2+ stores that had been fully and irreversibly emptied using the endomembrane Ca(2+)-ATPase inhibitor thapsigargin, both nucleotides produced a biphasic effect on Ca2+ entry, first r...

The mRNA encoding the cloned substance K receptor was microinjected into Xenopus laevis oocytes. After expression of the mRNA, Ca2+ was imaged in the oocytes with a digital imaging fluorescence microscopy system using the Ca2(+)-sensitive dyes fura-2 and fluo-3. Application of substance K caused a dose-related wave of Ca2+ mobilization to spread from a focus and to elevate the Ca2+ concentratio...

Control of cytoplasmic pH (pHi) by a Na+/H+ antiport appears a general property of most eukaryotic cells. In human platelets activation of the Na+/H+ exchanger enhances Ca2+ mobilization and aggregation induced by low concentrations of thrombin (Siffert, W., and Akkerman, J. W. N. (1987) Nature 325, 456-458). Several observations indicate that the exchanger is regulated by protein kinase C. (i)...

AIMS The aim of the study was to obtain further information regarding the modes of action of doxazosin, naftopidil and nifedipine on platelet function. METHODS We conducted an in vitro study of drug influences on adrenaline and collagen-induced mobilization of platelet calcium. RESULTS In the presence of fibrinogen (300 micrograms ml-1) both collagen (5 micrograms ml-1) and adrenaline (16 m...

Intracellular free Ca2+ [( Ca2+]i) and pH (pHi) were measured simultaneously by dual wavelength excitation in thrombin-stimulated human platelets double-labeled with the fluorescent probes fura2 and 2',7'-bis(carboxyethyl)-5,6-carboxyfluorescein to determine the relationship between changes in [Ca2+]i and pHi, respectively. At 37 degrees C, thrombin (0.5 or 0.1 units/ml) increased [Ca2+]i with ...

We have examined the ability of extracellular ATP to elicit intracellular Ca2+ mobilization in a broad range of human leukocytes at particular stages of hematopoietic differentiation. The average cytosolic [Ca2+] in various leukocyte populations was measured in Fura 2-loaded cell suspensions while the cytosolic [Ca2+] in individual, Indo 1-loaded leukocytes was assayed by flow cytometric method...

Internalization and phosphorylation of G protein-coupled receptors (GPCR) are considered two important regulatory events of receptor signal transduction. In Fischer rat thyroid (FRT) epithelial cells, we have shown that muscarinic acetylcholine receptor (mAChR) stimulation induces intracellular Ca2+ mobilization via Ca2+ store release, capacitative Ca2+ entry and voltage-dependent Ca2+ channels...

Rheumatoid arthritis synovial fibroblasts (RASFs) are fundamental effector cells in RA driving the joint inflammation and deformities. Celastrol is a natural compound that exhibits a potent anti-arthritic effect promoting endoplasmic reticulum (ER) stress mediated by intracellular calcium (Ca2+) mobilization. Ca2+ is a second messenger regulating a variety of cellular processes. We hypothesized...

The stimulation of hepatocytes by alpha 1-adrenergic agonists and vasoactive peptides results in a mobilization of intracellular Ca2+ which is accompanied by breakdown of phosphatidylinositol 4,5-bisphosphate to release myo-inositol 1,4,5-trisphosphate (Ins(1,4,5)P3). The possible involvement of Ins(1,4,5)P3 in intracellular Ca2+ mobilization was tested using a preparation of saponin-permeabili...