Millimolar concentrations of free magnesium enhance exocytosis from permeabilized rat pheochromocytoma (PC 12) cells

Millimolar concentrations of free magnesium enhance exocytosis from permeabilized rat pheochromocytoma (PC 12) cells.

The role of Mg2+ during the final steps of exocytosis was investigated using rat pheochromocytoma cells (PC12) permeabilized with bacterial pore forming toxins. Concentrations of free Mg2+ between 0.2 and 2 mM slightly lowered the basal but greatly enhanced the [3H]dopamine release elicited by 8 microM free Ca2+. Maximal effects were obtained at approximately 1 mM free Mg2+. At higher concentra...

Minimal requirements for exocytosis. A study using PC 12 cells permeabilized with staphylococcal alpha-toxin.

The membrane-permeabilizing effects of streptolysin O, staphylococcal alpha-toxin, and digitonin on cultured rat pheochromocytoma cells were studied. All three agents perturbed the plasma membrane, causing release of intracellular 86Rb+ and uptake of trypan blue. In addition, streptolysin O and digitonin also damaged the membranes of secretory vesicles, including a parallel release of dopamine....

Protective Effect of Quercetin against Oxidative Stress-Induced Cytotoxicity in Rat Pheochromocytoma (PC-12) Cells.

Oxidative stress has been implicated in the pathogenesis of many kinds of neurodegenerative disorders, particularly Parkinson's disease. Quercetin is a bioflavonoid found ubiquitously in fruits and vegetables, and has antioxidative activity. However, the underlying mechanism of the antioxidative effect of quercetin in neurodegenerative diseases has not been well explored. Here, we investigated ...

Kinetic characterization of guanine-nucleotide-induced exocytosis from permeabilized rat mast cells.

We have measured the time course of secretion of hexosaminidase from rat mast cells permeabilized (in simple buffered NaCl solutions) in response to guanine nucleotides [GTP or guanosine 5'-[gamma-thio]triphosphate (GTP[S])] and Ca2+. In these experiments, ATP was excluded from the system (and the cells were pretreated with metabolic inhibitors). For cells permeabilized in the absence of Mg2+ b...

Modulation of Ca 2 + - independent , Pb 2 + - induced exocytosis from rat PC 12 cells by CaMK II