title: Age-related effects of dexamethasone administration in adrenal zona reticularis.
abstract: Suppression of adrenocorticotropic hormone results in reduced adrenal steroid output, adrenocortical cell atrophy, and apoptosis in young rats. To verify such effects during aging, dexamethasone was injected into rats for 3 days at five different ages; at day 4, adrenals and blood were collected for morphologic and corticosterone assay. Adrenal structure was similar at all ages, but in dexamethasone-injected animals there were ultrastructural features of apoptosis and a higher percentage of TUNEL and caspase-3-labeled nuclei and cytoplasm; their corticosterone decreased significantly. In both groups, there was age-related decrease in the percentage of apoptotic cells, significant only in dexamethasone-injected rats. The data suggest that aged adrenocortical cells are less susceptible to the lack of adrenocorticotropic hormone (ACTH), possibly as a result of their decreased functional ability.
authors.affiliation: Laboratory for Molecular Cell Biology, Faculdade de Medicina do Porto, Portugal. almeidah@med.up.pt
authors.forename: Henrique
authors.initials: H
authors.lastname: Almeida
authors.forename: Liliana
authors.initials: L
authors.lastname: Matos
authors.forename: Jorge
authors.initials: J
authors.lastname: Ferreira
authors.forename: Delminda
authors.initials: D
authors.lastname: Neves
mesh_terms: D000311:Adrenal Glands / Q000187:drug effects* / Q000473:pathology / Q000648:ultrastructure; D000375:Aging / Q000187:drug effects*; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D002467:Cell Nucleus / Q000473:pathology; D048429:Cell Size; D003345:Corticosterone / Q000032:analysis / Q000097:blood; D003907:Dexamethasone / Q000008:administration & dosage / Q000494:pharmacology*; D007150:Immunohistochemistry; D008297:Male; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D015385:Zona Reticularis / Q000187:drug effects* / Q000473:pathology / Q000648:ultrastructure
chemical_list: D000893:Anti-Inflammatory Agents; D003907:Dexamethasone; D003345:Corticosterone