Effect of compression on rat-liver mitochondrial membranes. A biochemical and morphological study

When rat-liver mitochondria are subjected to compression at 0 degrees C, they become permeable to sucrose and the latency of malate dehydrogenase disappears. Freeze fracture electron microscopy shows smooth areas devoid of particles in fracture faces of the membranes. The effects of pressure can be inhibited as the temperature increases. Such results are explained by supposing that compression increases the transition temperature of mitochondrial membrane lipids above 0 degrees C and causes their freezing.