Effects of membrane depolarization and divalent-cations on anaphylactic histamine secretion

Description

The effects of membrane depolariz.ation and divalent cations on histamine release have been studied in sensitized mast cells. Membrane potential of these cells has been measured with intracellular microelectrodes. Our results show that mast cells have a large resting potential (-61512 mV) however they do not generate active membrane electrical responses when are depolarized by passing current through the recording microelectrode. High external K+ does not increase histamine release. Histamine secretion is supported by alkaliearth divalent cations (Ca2+> Sr2+>Ba2+) but strongly inhibited by transition metals. Ca2+ concentrations above 1 mM inhibit histamine release, however, this effect is not mimicked by Sr2+ and Ba2+.

Additional details