On-column monitoring of secretion of catecholamines from single bovine adrenal chromaffin cells by capillary electrophoresis.

The secretion of catecholamines from individual bovine adrenal medullary cells was quantitatively monitored by capillary electrophoresis with laser-induced native fluorescence detection. By using a physiological balanced-salt solution as the running buffer for CE, the amount of norepinephrine (NE) and epinephrine (E) secreted by their physiological secretagogue, acetylcholine, and the amount remaining in a single cell can be simultaneously quantified. Among the six different glands (from separate cows) studied, a predominance of E-rich cells were found. There was no apparent relationship between the ratio of NE/E released and the original NE/E content in the cell. The secretion process was also monitored dynamically with this method by continuously passing acetylcholine over the cell during stimulation. From the peak width and shape of the released material, one can estimate the time scale of the release process.