Background: This study was performed to investigate the light microscopic features of sustentacular cells in adrenal medulla in neonatal and adult male albino rats using an antibody against S-100 protein. S-100 expression in sustentacular cells is considered a reliable cell marker for this type of cells.
Materials and methods: Twenty-four male albino rats were allocated into two groups, neonatal group (1 week old, 12 rats) and adult group (3 months old, 12 rats). Paraffin sections of the adrenal glands were immunostained for the expression of S-100 protein.
Results: The results demonstrated differences in distribution, arrangement and structure of sustentacular cells in adrenal medulla in neonatal and adult rats. All sustentacular cells of adrenal medulla in all animals showed intense immunoreactivity for S-100 protein in their nuclei, perikarya, and cytoplasmic processes. Most of S-100 immunopositive sustentacular cells in adrenal medulla of neonatal rats are few, dispersed, small in size, and oval in shape with thin short bipolar cytoplasmic processes. These cells in adult rats are more numerous, larger in size, and stellate in shape with numerous slender, longer branched cytoplasmic processes.
Conclusions: This study indicated that adrenal medullary sustentacular cells showed obvious morphological postnatal changes with aging suggesting structural and functional maturation.
Keywords: S-100 protein; adrenal medulla; immunohistochemistry; rat; sustentacular cells.