Abstract
The authors observed substance P-, somatostatin- and β-endorphin-like immunoreactivities ultrastructurally in the perikarya of the primary sensory ganglion cells by means of Nakane's enzyme-labeled antibody technique. As the results, the immunoreactivities of the neuropeptides were observed as irregularly shaped masses always encapsulated with membrane-bound contours of which diameters were 200nm to 2μm. Such neuropeptide-containing immunoreactive masses encapsulated by the membrane were usually seen in the vicinity of the Golgi apparatus. These immunoreactivities of the neuropeptides were more often observed in smaller nerve cells, though they were sometimes observed in the larger ones, too.
The authors also observed substance P- and somatostatin-like immunoreactivities in the Rexed's lamina II in the posterior horn of the spinal cord as nerve terminals. Substance P- and somatostatin-containing nerve terminals were often stained diffusely by positive immunoreactivity and within them there were denser immunoreactive vesicles uniform in size. These electron dense vesicles with positive immunoreactivity were noted along the nerve axon to the terminal.