Abstract
The ultracytochemical localization of 3β-hydroxysteroid dehydrogenase (3β-HSD) and glucose-6-phosphate dehydrogenase (G6PD) was investigated in cells of the rat adrenal cortex using copper ferrocyanide. After incubation in a 3β-HSD medium, final reaction products of copper ferrocyanide were observed in the cytoplasmic matrix near the smooth endoplasmic reticulum (SER) and in the intracristal spaces of mitochondria of the fascicular zone and reticular zone. No deposits appeared in the Golgi apparatus or nuclei. Cells of the glomerular zone were devoid of enzyme activity. The final reaction products of copper ferrocyanide of the G6PD activity were found mainly in the cytoplasmic matrix in the vicinity of the plasma membrane of the fascicular zone. Some cells of the glomerular zone demonstrated the same reaction products in the cytoplasmic matrix. This finding was consistent with the fact that G6PD is a cytoplasmic enzyme. The result of our ultracytochemical study on the localization of 3β-HSD activity has not always been in accord with the biochemical data in cell fraction reporting that most of the 3β-HSD activity is associated with the microsomal fraction.
