Quantitative and immunohistochemical studies on supporting cells in the rat and pig adrenal medullae

The number and chemical nature of supporting cells were examined in the adrenal medulla of the pig and rat. Cryostat sections of adrenal medullae fixed with Zamboni fluid were immunostained by the ABC method using antisera to PNMT, S-100 protein and GFAP. The relative number of nonchromaffin cells to total intraparenchymal cells was higher in NA-cell regions (pig: 22.3 ± 1.3%; rat: 20.2 ± 0.7%) than in A-cell regions (9.5 ± 0.7%; 7.9 ± 0.5%) in both species. In the pig adrenal medulla, the numerical ratio of S-100 proteinimmunopositive cells to total nonchromaffin cells was higher in NA-cell regions (91.0 ± 1.9%) than in A-cell regions (29.9 ± 2.2%). In the rat, the ratios of S-100- and GFAP-positive cells were almost similar in NA-cell regions (S-100: 81.5 ± 2.6%; GFAP: 78.2 ± 2.3%), but difference in A-cell regions (32.4 ± 3.7%; 16.2 ± 2.5%, P<0.0001). Conclusion: In both pigs and rats, the occurrence frequency of supporting cells was higher in NA-cell regions than in A-cell regions, and the numerical ratio of cells showing glial marker (S-100 protein), or GFAP in rats, to total nonchromaffin cells was higher in NA-cell regions than in A-cell regions. It seems likely that at least two subpopulations exist in supporting cells in rats, especially in A-cell regions. (J.Aomori Univ.Health Welf.2:47 -52, 2000)