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

Wegenhorst, U.; Gratzl, Manfred; Föhr, K. J. and Ahnert-Hilger, G. (1989): Millimolar concentrations of free magnesium enhance exocytosis from permeabilized rat pheochromocytoma (PC 12) cells. In: Neuroscience Letters, Vol. 106: pp. 300-304

Abstract

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 μM free Ca2+. Maximal effects were obtained at approximately 1 mM free Mg2+. At higher concentrations Mg2+ was less potent. Similar effects of Mg2+ were obtained in cells permeabilized either for small molecules (by α-toxin) or for large ones (by streptolysin O). It is concluded that millimolar concentrations of cytoplasmic Mg2+ play an important role in Ca2+ triggered exocytosis.

• Item Type: Journal article
• Keywords: Permeabilization, Rat pheochromocytoma, Exocytosis, Calcium, Magnesium
• Faculties: Medicine
• Subjects: 600 Technology > 610 Medicine and health