Abstract
In the present study, the immunohistochemical expression of vasoactive intestinal polypeptide (VIP) in the parotid gland of rats exposed to fractionated irradiation was examined. VIP concentration was analyzed by radioimmunoassay (RIA). Irradiation lead to a marked increase in the immunohistochemical expression of VIP in the innervation of the gland parenchyme. VIP-like immunoreactivity (LI) frequently coexisted with SP (substance P)-LI in these nerve fibers. The pattern of VIP-innervation in association with large ducts and blood vessel walls was unchanged. RIA analysis revealed a more than three-fold elevation in VIP content in the gland in response to irradiation. The increase in VIP immunoreaction and VIP content was seen at examination ten days after cessation of a five-day treatment with a total dose of 30–40 Gray. The upregulation of VIP may be related to changes in the production of neurotrophic factors and to an increased demand for a potentiation of secretagogue effects of SP.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
