Cardiovascular system reactions and bioenergy metabolism in relation to adaptation to apnea

: Responses of the cardio-vascular system and bioenergetic metabolism were studied in the heart tissue in apnoea in naturally adapted to diving musk-rats and unadapted rats and mice. A sharp bradycardia was shown to develop in former animals in arresting a breathing as well an increase in the neutrophils contents in the blood. The data obtained suggest that release of the necessary oxygen and antiradical defence functions can be related to the catalase activity.