Restoration of heart and respiration in rats after cooling to a body temperature of 9-10°C

Abstract

The study was carried out on male Wistar rats anesthetized by urethane. The rats were cooled in water until breathing stopped; after 5 minutes, mechanical ventilation of the lungs was started, which activated the work of the heart. The animals were not removed from the water, the heart rate decreased, the heart stopped at rectal temperature (Tr) 9,6±0,7°, in the esophagus (Te) 11,9±0,6°C. Then the rats were taken out of the water, a saline heating pad (38-40 °C) was applied to the chest area. As a result, the heart temperature increased, the heart rate began to rise; their own respiration appeared at Tp 18,6±0,8° and Te 21,6±0,9°C. It is concluded that the supply of oxygen to the heart and warming contribute to the restoration of its work, and the resumption of its own breathing. Key words: hypothermia, rat, artificial respiration, heart, respiration.