Immunohistochemical evidence for the occurrence of vasoactive intestinal polypeptide (VIP)-containing nerve fibres in human fetal abdominal paraganglia.

The abdominal paraganglia in man represent a major source of catecholamines, and perhaps peptide hormones, during the fetal period. The nature of the innervation of the abdominal paraganglia was studied immunohistochemically by utilising antibodies to vasoactive intestinal polypeptide, enkephalin, substance-P and somatostatin. The paraganglia showed an abundant network of VIP-immunoreactive fibres, and similar nerve fibres were found within nerve bundles of the preaortic sympathetic plexus. Occasionally, VIP-immunoreactive fibres were seen within the prevertebral ganglia, but stained cell bodies were never observed. It may be suggested that VIP-containing nerves could regulate a secretory response from fetal human abdominal paraganglia.