BIOCHEMICAL STUDIES ON BRAIN SWELLING I. CHANGES IN RESPIRATORY CONTROL 2,4‐DINITROPHENOL INDUCED ATPase ACTIVITY AND PHOSPHORYLATION — Correlation between Brain Swelling and Mitochondrial Function —

Summary Brain swelling was produced by exposing the cerebral cortex to air (rat) and by epidural compression (cat). The isolated mitochondria from swollen brains were investigated with regard to some basic properties relevant to their functional state, such as respiration, phosphorylation, respiratory control and ATPase activity. The biochemical findings correlated with clinical and electroencephalographic findings. In the moderate cases, the isolated mitochondria revealed a loosely coupled state of the oxidative phosphorylation, characterized by a decrease of respiration in the presence of a phosphate acceptor, with an essentially normal phosphorylative efficiency. The ATPase activity of the mitochondria was only slightly stimulated by 2,4‐dinitro‐phenol. On the other hand, the mitochondria of severe cases showed loss of phosphorylation, but in some cases, the improvement of phosphorylation was observed when serum albumin was added or the mitochondrial preparation was kept at 0 for two hours. The possible mechanism of the development of brain swelling was discussed from the viewpoint of the biochemical change in the mitochondria.