Water Exchanges of Isolated Mammalian Tissues at Low Temperatures

¹ From the Department of Physiology, School of Medicine and Dentistry, The University of Rochester, Rochester, New York

Water exchanges of thin tissues from rats and ground squirrels were influenced by temperature, anoxia and storage. Kidney, liver, auricle and diaphragm were removed from precooled animals; kidney and liver were also sliced. Changes of tissue weights were measured with a torsion balance. At 6° or 16° tissues took up water from saline solution that was isotonic at 36°. Both warmth and oxygen were needed to resist this swelling, and the changes due to cold or anoxia or cyanide were reversible. Evidently water was expelled from the tissue, and probably from its cells, through a process dependent on oxidative metabolism and warmth. The reversal of swelling served as one test of tissue survival. Within an hour or two before immersion the control of water exchanges suffered no permanent damage from cold or anoxia, but over longer periods of time damage resulted.