Abstract
The activities of Δ5-3β-hydroxysteroid dehydrogenase (3β-HSD; EC 1.1.1.51) and glucose-6-phosphate dehydrogenase (G-6-PDH; EC 1.1.1.49) in the adrenal cortex of virgin rats during the estrous cycle were measured by microspectro-photometry.
3β-HSD activity was found throughout the cortex, and was especially high in the outer part of the zona fasciculata and the juxtamedullar cell layer during estrus. The HSD-positive cells had a high lipid content, a well developed smooth endoplasmic reticulum (SER) and globular mitochondria with many vesicular cristae. Reaction products of 3β-HSD were found on the outer surface membrane of the SER, and in the cristae of the mitochondria, particularly in the swollen cristae.
The distribution of G-6-PDH was similar to that of 3β-HSD.
These results suggest that steroidogenesis in the adrenal cortex increases in estrus, activating both the SER and mitochondria in cells of the zona fasciculata and the juxtamedullar cell layer.
