Calcium-dependent exocytosis in bovine adrenal medullary cells with leaky plasma membranes

Further Characterization of Dopamine Release by Permeabilized PC 12 Cells

“…Permeabilization not only by high-voltage discharge (Baker and Knight, 1978) or by saponins (Dunn and Holz, 1983;Brooks and Treml, 1983a;Wilson and Kirshner, 1983) but also by atoxin from Staphylococcus aureus can be used to gain access to the cytoplasm (Ahnert-Hilger et al, 1985a,6;Bader et al, 1986;Lind et al, 1987). The toxin produces stable pores in the plasma membrane that are too small to let the monomer pass and attack subcellular organelles (Fussle et al, 1981; for review see Bhakdi et al, 1981;Bhakdi and Tranum-Jensen, 1987).…”

Interaction of chromaffin granules with plasma membranes mediated by Ca2+ and Mg2+‐ATP using self‐generating gradients of percoll®

“…(The 'lighr granules' found in 1143 are possibly aggregates between granules and plasma membranes and identical to our low density populatron of granules.) Physiologically, CaZ* and Mg-ATP are essential and specific for exocytotic release of the granular content [3]. These in vitro data suggest that at cytoplasmati~ Ca2* levels (IO-' M) complexes between granules and plasma membranes are stable and that at higher Ca'+ levels (1 OTS-l 0 -4 M) in the presence of Mg-ATP there is a separation of granules from the plasma membranes.…”

“…The gradient solutions of 60 vol.% Percoll@ (Pharmacia) contain 6 ml original Percoll@ suspension and 4 ml buffer A' [3] (or B' [4]); final pH is 6.6.0.5 ml Aliquots of resuspended pellets PZ were mixed with 9 ml Percoll@ suspension and each sample was centrifuged at 50 000 X g, 30 min, at 2°C (in polycarbonate tubes, Ti 50 rotor, Beckmann-Spinco UC). The pellet material distributed in the self-generated PercoIl@ gradient was transferred to a fraction collector (LKB) by pumping out with a 2 M sucrose solution at constant speed; the fraction size was 0.4 ml.…”

Glucose transporters in chromaffin cells: Subcellular distribution and characterization

“…Two main possibilities exist (i) during the organelle biogenesis or (ii) after the exocytotic event when the plasma and chromaffin granule membranes undergo exocytosis for recycling. In both cases incomplete separation between the regulated and constitutive exocytotic pathways could be supposed [27,28].…”