Abstract
Immunohistochemical localization and biochemical activity of glutathione peroxidase (GSH-PO) in rat adrenal glands were studied on 1) normal untreated, 2) hypophysectomized and 3) ACTH administered groups in order to clarify the role of GSH-PO in the adrenocortical lipid metabolism. In the normal untreated group, GSH-PO was immunohistochemically localized in the zonae fasciculata and reticularis of the adrenal cortex. The hypophysectomized group showed marked atrophy of these zones which contained accumulated cholesterol esters. Thin layer chromatography of this group showed the presence of sterol hydroperoxides in mitochondrial, cytosol and microsomal fractions. Immunohistochemically, GSH-PO was localized in these atrophic zones. On ACTH administration, the numbers of GSH-PO positive adrenocortical cells were increased and the staining was more intensified. The activity of GSH-PO was higher in this group than in the control group.
These findings suggested that GSH-PO in the rat adrenocortical cells may be playing an important role in reduction of both lipid peroxides such as cholesterol ester hydroperoxides in the reparative process of cell injury (hypophysectomy) and steroid hydroperoxides during steroidogenic process (ACTH administration).
