Blood Pressure and Heart Rate During Natural Sleep of the Cat and Their Regulation by Carotid Sinus and Aortic Reflexes

摘要

Blood pressure and heart rate changes during the wakefulness-sleep cycle were studied in 24 unanesthetized free-moving cats, carring an implanted cannula in a femoral artery as well as electrodes for electroencephalographic, electromyographic and eye movement recording. In 14 animals sino-aortic deafferentation was performed. Quantitative evaluation of all data was carried out by analysis of variance. Both in intact and in deafferented animals, light sleep was accompanied by a slight but definite decrease in systolic and diastolic pressures, and in heart rate. While both arterial pressure and heart rate showed a consistent trend to increase toward the end of light sleep and at the very beginning of deep sleep, a large fall in arterial pressure and heart rate were always observed during deep sleep. Blood pressure and heart rate were also more variable during deep than during light sleep. Systolic and diastolic pressures, as well as heart rate, were significantly higher in deafferented than in intact animals both during quiet wakefulness and throughout light sleep. However, such surprisingly large falls in pressure were recorded during the course of deep sleep episodes that arterial pressure finally attained much lower absolute values in deafferented than in intact animals. In several incidents of the lowest values of blood pressure, episodes of transient cerebral ischemia (electroencephalographic flattening and seizures) occurred.