The effects of the ionophore, X537A, and caffeine on ATP-dependent calcium transport by fragmented sarcoplasmic reticulum were studied in the absence (calcium storage) or presence (calcium uptake) of calcium-precipitating anions. The ionophore caused rapid calcium release after calcium storage, the final level of calcium storage being the same whether a given concentration of X537A was added pr...

The effects of vasopressin, angiotensin II, and calcium ionophore A23187 were examined and compared on endogenous prostaglandin E2 (PGE2) production, in the absence of exogenous arachidonate, by glomeruli and cortical and medullary collecting tubules freshly prepared from rat kidney. Angiotensin II stimulated PGE2 production in the glomeruli but not in the collecting tubules. Vasopressin at con...

The coagulant activity of tissue factor (TF) in the membranes of cultured cells is increased after physical disruption of the cells, and a similar increase can be elicited by treatment of cell cultures with calcium ionophore and calcium. We observed that the supernatants of cultures treated with calcium and ionophore 4-Br-A23187 contained more TF activity than those of control cultures. Phase c...

Herein, we present the first example of a benzimidazolium-based artificial transmembrane chloride transporter and a synthetic calcium ionophore that can regulate intracellular calcium concentrations in bacteria.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterized by the progressive loss of motor neurons leading to paralysis and death. Mutations of the human Cu/Zn superoxide dismutase (SOD1) are found in some cases of familial ALS (fALS). Recent evidences suggest the accumulation of intracellular calcium is one of the primary mechanisms of motor neuronal degeneration. In th...

Four sesquiterpenes isolated from Jasonia glutinosa D.C. (Asteraceae), namely lucinone, glutinone, 5-epi-kutdtriol and kutdtriol, have been evaluated for their in vitro anti-inflammatory activity in cellular systems generating cyclooxygenase (COX) and 5-lipoxygenase (5-LOX) metabolites. None of the compounds assayed had a significant effect on leukotriene C4 (LTC4)-release from calcium ionophor...

T cell stimulation by triggering through the T cell receptor (TCR) in the absence of costimulatory signals or by calcium ionophore induces unresponsiveness in T cells to further stimulation, a phenomenon known as anergy. In freshly isolated T cells, calcium ionophore induces expression of interleukin (IL)-2 messenger (mRNA), but this mRNA is not translated and not loaded with ribosomes. In addi...

The divalent cation ionophore A 23187 was used to evaluate the action of intracellular calcium on net transepithelial water movement across the isolated frog urinary bladder. Incubation with the ionophore increases the net basal water flux in a dose-dependent fashion but independent of the extracellular calcium concentration. Bladders pretreated with A 23187 and exposed thereafter to an increas...

The immunosuppressant hormone dexamethasone (Dex) interferes with T cell-specific signals activating the enhancer sequences directing interleukin 2 (IL-2) transcription. We report that the Dex-dependent downregulation of 12-O-tetradecanoyl-phorbol-13-acetate (TPA) and calcium ionophore-induced activity of the IL-2 enhancer are mediated by glucocorticoid receptor (GR) via a process that requires...