抄録
Immunocytochemical localization of glutathione-reductase (GSSG-RD) in rat adrenal glands was studied in 1) normal untreated, 2) hypophysectomized, and 3) ACTH administered groups in order to clarify the biological significance of GSSG-RD in the adrenal cortical lipid metabolism including steroidogenesis. In the normal untreated group, GSSG-RD was immunohistochemically localized in all three zones of the adrenal cortex. In immunoelectron microscopic investigations, GSSG-RD was observed mainly in mitochondria. The hypophysectomized group showed atrophy of the zonae fasciculata and reticularis. GSSG-RD staining of the atrophic cortical zones was weakened. In immunoelectron microscopic investigations, GSSG-RD was observed not only in mitochondria but also in cytoplasmic matrix. On ACTH administration, the adrenal cortex became markedly hypertrophic, especially in the outer fasciculata. Immunohistochemically, GSSG-RD was mainly localized in the cells of those hypertrophic cortical zones. In immunoelectron microscopic investigations, GSSG-RD was observed not only in mitochondria but also in cytoplasmic matrix. These staining patterns were similar to those of glutathione-peroxidase (GSH-PO). GSH-PO reduces the lipid peroxides with concomitant oxidation of glutathione. Oxidized glutathione is reduced by GSSG-RD under the presence of NADPH. These two enzymes are known to be key enzymes of the lipid peroxides scavenging system. Based on our findings, it is strongly suggested that a very close relationship lies between the adrenal cortical GSSG-RD and steroidogenesis.
