T. Kitanishi et al., Immunohistochemical detection of vasoactive intestinal polypeptide (VIP) and the VIP receptor in the rat inner ear, ACT OTO-LAR, 1998, pp. 52-56
Vasoactive intestinal polypeptide (VIP) is a 28 amino acid peptide that was
originally isolated from porcine duodenum. The presence of VIP has been de
monstrated in the central nervous system and peripheral tissues. However; t
here have been feu, reports on VIP as a neurotransmitter, especially in the
inner ear. To investigate the function of VIP in The rat inner ear, we exa
mined the expression of VIP and the VIP receptor by immunohistochemistry. U
sing the anti-VIP and VIP receptor antibodies, scattered fibres Fn the coch
lear nerve trunk demonstrating VIP-like immunoreactivity were found, and th
e spiral ganglion cells demonstrated ring-shaped VIP-like immunoreactivity.
Immunoreactivity for the VIP receptor was predominantly found in the spira
l ganglion cells. Our results suggest that VIP may play an important role a
s a possible neurotransmitter not only in the local control of cochlear blo
od flow, but also in the auditory system.