Chaminade_1983_Life.Sci_33 Suppl 1_21

In the present study we have carefully determined the nature and amount of enkephalin immunoreactive product co-related with catecholamines by the cat adrenal gland perfused in-situ. Met-enkephalin immunoreactivity (IR) and total Met-enkephalin-IR obtained after digestion of large enkephalin containing peptides were released by electrical stimulation of the splanchnic nerves, with 0.1 mM acetylcholine perfusion or 50 mM K+. We have found that in response to splanchnic nerve stimulation 47% of enkephalinergic material was on the form of small peptide (Met-enkephalin, Leu-enkephalin, heptapeptide, octapeptide). When drastic stimuli like perfusion with 50 mM or 0.1 mM acetylcholine were used, the bulk of the enkephalinergic material was present on the form of large fragments of the precursor. These results are interpreted as follows: when physiological stimuli are used, mature granules containing fully processed precursor are released; when drastic chemical stimuli are applied, unmature granules containing partially processed precursor are also released.