Studies on respiratory enzymes of the adrenal gland. II. The cortex.

On the basis of his observations with the hand spectroscope, Huszák (1) stated that the adrenal cortex contained cytochromes c, b, and a + a3, as well as an unknown cytochrome absorbing between cytochromes b and c. The present study has attempted to define both the cytochromes present in the beef adrenal cortex, as well as their distribution among the cell fractions. It confirms the presence of cytochromes c, b, and a + a3, and indicates the likelihood that cytochrome cl is the unknown cytochrome mentioned by Huszák. All of these cytochromes are present in the cortical mitochondria, and it has not been possible to demonstrate the presence of a microsomal cytochrome in the cortex such as is present in the microsomes of liver (2) or of the adrenal medulla (3). A survey has also been made of several of the respiratory enzymes of the cortex. Similar to what has already been reported for the adrenal medulla (3), it showed that the enzymes responsible for the transfer of electrons to O2 from reduced triphosphopyridine nucleotide are of much lower activity than those responsible for the production of this reduced coenzyme. Such a relationship is fitting in view of the synthetic requirements for reduced triphosphopyridine nucleotide in the various hydroxylation steps of steroid biosynthesis (4, 5).