抄録
Histochemical and immunohistochemical studies of the adrenal gland of bullfrogs gave the following results.
1. The occurrence of two types of cells, intensely and weakly chromaffin cells, was demonstrated by a dichromate-chromate fixation. The former cells corresponded to strongly argentaffin cells in Masson-Hamperl's method and were regarded as noradrenaline-containing cells. The latter cells corresponded to weakly argentaffin cells and were identified as adrenaline-containing cells.
2. Enkephalin- and serotonin-like immunoreactivities were found in the adrenal chromaffin cells. The combination of immunohistochemistry and fluorescence histochemistry indicated three types of cells in the adrenal gland: cells with adrenaline and serotonin; those with noradrenaline and serotonin; and those with adrenaline, enkephalin and serotonin.
3. Varicose nerve fibers with substance P-, calcitonin gene-related peptide (CGRP)-, peptide HI (PHI)- and gastrin releasing peptide (GRP)-like immunoreactivities were found on solitary or small clustered chromaffin cells. The CGRP-fibers were also located among chromaffin cells forming large clusters. Neuropeptide Y (NPY)-immunoreactive fibers, as well as the other four fibers, were seen around the small arteries and arterioles supplying the adrenal gland.
4. Double immunostaining for substance P and CGRP demonstrated the occurrence of nerve fibers with three kinds of immunoreactivities in the adrenal gland: fibers with both substance P- and CGRP-like immunoreactivities; those with substance P-like immunoreactivity without CGRP-like immunoreactivity; and those with CGRP-like immunoreactivity without substance P-like immunoreactivity. Double staining for substance P and CGRP also showed the presence of dorsal root ganglionic neurons which contained the three above-mentioned immunoreactivities. Thus, these neurons are suggested to supply the adrenal gland.
5. In the paravertebral sympathetic ganglia, most small neurons were immunopositive for NPY. These neurons were presumed to supply the small arteries and arterioles in the adrenal gland.
