Almudena Albillos

TL;DR: Exocytosis of individual chromaffin granules is investigated by using cell-attached capacitance measurements, combined with electrochemical detection of catecholamines, achieved by inserting a carbon-fibre electrode into the patch pipette and finding that the fusion-pore diameter stays at <3 nm for a variable period, which can last for several seconds, before it expands.

TL;DR: It is shown that half of the chromaffin-cell mitochondria exhibit surprisingly rapid millimolar Ca2+ transients upon stimulation of cells with acetylcholine, caffeine or high concentrations of potassium ions, indicating that mitochondria modulate secretion by controlling the availability of Ca2+, for exocytosis.

TL;DR: The results are compatible with the presence in bovine chromaffin cells of a Q‐like Ca2+ channel which has a prominent role in controlling exocytosis and suggest that Q‐ and L‐type Ca 2+ channels, but not N‐ or P‐types are localized near exocyTotic active sites in the plasmalemma.

TL;DR: The observed mitochondrial Ca2+-induced Ca2-induced release response was insensitive to cyclosporin A and CGP37157 but fully blocked by ruthenium red, suggesting that it may be mediated by reversal of the Ca2 + uniporter.

TL;DR: The data suggest that the whole cell IBa in rat chromaffin cells exhibits at least four components, which differ considerably from those found in bovine chromaff in cells, where P-like Ca2+channels account for 45% of the current, N-type carry 35% and L-type Ca2- channels are responsible for only 20–25% ofThe drastic differences might have profound physiological implications for the relative contribution of each channel subtype to the regulation of catech