Chromogranin A processing in sympathetic neurons and release of chromogranin A fragments from sheep spleen

Abstract
Chromogranin A (CGA) has been localized to the large dense cored vesicles (LDV) of sympathetic neurons. SDS‐PAGE and immunoblotting of soluble LDV proteins from ox and dog adrenergic neuronal cell bodies, axons and nerve terminals, revealed an increasing number of CGA‐immunoreactive forms, consistent with proteolytic processing during axonal transport. Splenic nerve electrical stimulation (10 Hz, 2 min) revealed that, apart from CGA. these CGA‐processing products are released from the sheep spleen. The secretion of CGA‐derived fragments from sympathetic neurons might suggest a role in the regulation of synaptic transmission.