Cytological maturity of zona fasciculata cells in the fetal sheep adrenal following ACTH infusion: an electron microscope study.
Electron microscopy was used to assess the cytological maturity of the zona fasciculata cells in the adrenal cortex of fetal sheep at 105 days of gestation, following several ACTH infusion regimes. The aim of this study was to correlate the morphological appearance of the fetal adrenal zona fasciculata cells with the expression of the steroid hydroxylase genes and the fetal plasma cortisol concentrations in a parallel study. Immediately following infusion of ACTH for 24 or 72 h, the zona fasciculata cells at the cortico-medullary junction were more mature than those in the saline-infused controls. When ACTH infusions were withdrawn for 24-72 h prior to the termination of the experiment, the deep cortical cells appeared less mature than those in fetuses which had received ACTH right up until the time of tissue collection. Following ACTH administration, mitochondrial changes preceded changes in the smooth endoplasmic reticulum, and when ACTH was withdrawn, the smooth endoplasmic reticulum responded before the mitochondria. The study demonstrated a correlation between the cytological maturity of the deep zona fasciculata cells and the expression of the genes for the steroidogenic enzymes P-450(17)alpha and P-450scc in the 105-day fetal sheep adrenal following ACTH infusion.
Perry
R A
RA
Department of Anatomy, University of Melbourne, Parkville, Victoria, Australia.
Tangalakis
K
K
Wintour
E M
EM
D000311:Adrenal Glands / Q000196:embryology* / Q000201:enzymology / Q000648:ultrastructure; D000324:Adrenocorticotropic Hormone / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D002786:Cholesterol Side-Chain Cleavage Enzyme / Q000235:genetics; D004721:Endoplasmic Reticulum / Q000648:ultrastructure; D005260:Female; D015870:Gene Expression; D006854:Hydrocortisone / Q000097:blood; D008854:Microscopy, Electron; D008928:Mitochondria / Q000648:ultrastructure; D012756:Sheep; D013254:Steroid 17-alpha-Hydroxylase / Q000235:genetics; D013997:Time Factors; D015383:Zona Fasciculata / Q000166:cytology* / Q000648:ultrastructure
D000324:Adrenocorticotropic Hormone; D013254:Steroid 17-alpha-Hydroxylase; D002786:Cholesterol Side-Chain Cleavage Enzyme; D006854:Hydrocortisone