These investigations are part of an attempt to study and interpret the intermediary metabolism of the kidneys in experimental
renal hypertension.
Hypertension was produced in dogs by the clamping procedure of Goldblatt and associates or by the
silk perinephritis method of Page. Enzymatic studies were made by means of Warburg's manometric method.
Cytochrome c was in addition determined spectrophotometrically. Tissue slices, homogenized tissue, and
tissue extracts were used. A study of the
cytochrome c concentration and the activities of the
cytochrome oxidase and
succinic dehydrogenase systems of kidneys from normal dogs and dogs with experimental
renal hypertension was made. It was found that the
cytochrome c concentration and the activities of the
cytochrome oxidase and
succinic dehydrogenase systems were markedly lower in the kidney slices and in the tissue
suspensions from hypertensive dogs. Tissue
suspensions and extracts of kidneys from hypertensive dogs showed an inhibitory effect on the activity of the
cytochrome oxidase and
succinic dehydrogenase, and the
amine oxidase systems.
Renin preparations also showed a marked inhibitory effect on the activities of
cytochrome oxidase,
succinic dehydrogenase,
l-amino acid oxidase, and
amine oxidase systems. A significant increase was found in the kidney of dogs whose other kidney had been removed or subjected to Goldblatt's or Page's technique in the activities of the
cytochrome-
cytochrome oxidase system, the
succinic dehydrogenase system, and in the concentration of
nucleotide-bound
phosphorus, of
flavin-adenine dinucleotide, and of the
nicotinamide-
adenine dinucleotides (
coenzymes I and II). From the results of these studies it can be concluded that an increase in the concentration and activity of the respiratory
enzymes precedes
hypertrophy of the kidney. This can be explained by the assumption that an increase in the activity of the respiratory
biocatalysts acts as a stimulus for cell growth and multiplication.