Innervation of human adrenal gland and adrenal cortical lesions

The innervation of the human adrenal gland and of cortical lesions was studied in sections of cortical tissue (n=10), hyperplastic cortical tissue (n=3), and tissue from cortical adenomas (n=5) and carcinomas (n=6). The presence and distribution of nerve structures containing neuronal markers indicating sympathetic and parasympathetic innervation were studied by immunohistochemistry and the co-existence and co-localization patterns of the different markers by immunofluorescence. The cortex and hyperplastic cortical tissue had a moderate to rich supply of nerve structures containing the typical neuronal markers: protein gene product 9.5 (PGP 9.5), neuron-specific enolase (NSE), small vesicle synaptic protein type 2 (SV2), and nerves showing immunoreactivity to the adrenergic marker tyrosine hydroxylase (TH). All these immunoreactive nerves were located predominantly adjacent to blood vessels, but also among parenchymal cells. The cortex showed numerous nerve structures containing the neuropeptide substance P (SP), neuropeptide Y (NPY) and vasoactive intestinal protein (VIP), but few nerves containing these peptides were seen in hyperplastic cortical tissue. Typical markers were occasionally observed in cortical adenomas but were not found in carcinomas, except in a few cases where PGP 9.5 and NSE were present, but only adjacent to necrotic areas. Nerves containing NPY and VIP occurred in varying numbers in both adenomas and carcinomas. NPY- and VIP-immunoreactive nerve structures were seen mostly alongside blood vessels. There were several types of co-existence. For instance, NSE/VIP-, TH/VIP- and TH/NPY-immunoreactive nerve structures were often seen in the same trunk, but were only partly co-localized.