[3H]-noradrenaline secretion from rat cortex synaptosomes perforated with Staphylococcus aureus α-toxin

Rat cortex synaptosomes have been successfully perforated with high concentrations (greater than or equal to 400 U/ml) of Staphylococcus aureus alpha-toxin. The free Ca2+-concentration dependence of [H-3]noradrenaline release was similar to that observed for PC 12 and chromaffin cells. Release from the or-toxin perforated synaptosomes was not significantly inhibited by omega-conotoxin GVIA. Initially, Ca2+-dependent release was independent of MgATP (for 0.5 min), but became increasingly dependent on MgATP with time. Lactate dehydrogenase efflux from a-toxin-perforated synaptosomes was not different than efflux from control synaptosomes, and an antibody to N-ethylmaleimide-sensitive fusion protein did not enter the synaptosomes. [H-3]-noradrenaline release was temperature and cr-toxin-concentration dependent. Ca2+-dependent release was more resistant to rundown from alpha-toxinthan from streptolysin-O-perforated synaptosomes. This preparation of perforated synaptosomes should be useful for studies of regulated exocytosis from nerve endings. (C) 1998 Elsevier Science B.V. All rights reserved.