The localization of three catecholamine-synthesizing enzymes, tyrosine hydroxylase (TH), dopamine-β-hydroxylase (DBH) and phenylethanolamine-N-methyltransferase (PNMT) in some ganglia of dogs was studied by immunohistocytochemical methods.
The suprarenal and superior cervical ganglion cells showed TH-, DBH-positive and PNMT-negative or TH-positive, DBH- and PNMT-negative reactions by immunofluorescent staining. In the superior cervical ganglia, small numbers of TH-positive, small intensely fluorescent (SIF) cells formed clusters. By immunoelectron microscopy, TH-positive reaction products were observed in the cell matrix and granules of the superior cervical ganglion. In the nodose ganglion, small numbers of TH-positive, DBH-negative dopamine cells with varicose fibers were scattered among many TH-negative principal ganglion cells.
