Localization of immunoreactivities for neuropeptides and neurotransmitter-synthesizing enzymes in the pterygopalatine ganglion of the pig

Study on the presence of the selected biologically active substances in nerve structures of the porcine pterygopalatine ganglion was performed with the use of immunofluorescence and RT-PCR. All neurons in the ganglion were ChAT-, VAChT-, NOS- and VIP- positive. However, some neurons displayed strong immunoreactivity, while in other neurons, immunoreactivity was moderate, or weak. Somatostatin (SOM) was present in approx. 11% of neurons. Tyrosine hydroxylase-positive (TH-positive) neurons were not detected, although in single nerve cell bodies, TH antibody revealed very weak staining which could be attributed to some residual TH immunoreactivity. Immunoreactivity to NPY was found in 25% of all neuronal perikarya while PACAP was present only in 2-3% of them. More numerous neurons (6%) contained immunoreactivity to GAL. No neurons stained for SP or CGRP. Numerous ChAT-, VAChT-, NOS-, VIP-, and PACAP-positive, scarce SP and CGRP-positive, single SOM-, NPY- and GAL-positive nerve fibers were observed throughout the ganglion. No TH immunoreactivity was found in the nerve fibres. RT-PCR detected strong signal of the transcripts of ChAT, SOM, NOS, VIP, NPY, PACAP, and GAL. Only very weak signal was observed in case of TH, SP and CGRP. No RT-PCR was performed for VAChT message.