Interplay of sino-aortic reflexes and haemodynamic changes during natural sleep in the cat.
1. When the sino-aortic afferents are intact, desynchronized sleep causes a small decrease in the blood pressure, a vasodilation in the mesenteric and renal beds, and a vasoconstriction in the external iliac bed. 2. After sino-aortic deafferentation desynchronized sleep causes a larger fall in the blood pressure, a greater vasodilatation in the mesenteric and renal beds, and a vasodilatation replaces the vasoconstriction in the external iliac bed. 3. The sino-aortic reflexes play an active role in controlling circulation during desynchronized sleep by opposing the centrally induced reduction in adrenergic sympathetic tone. This effect of sino-aortic reflexes is similar on both visceral and muscular vessels. In addition, the muscular bed, but not the visceral one, is regulated by a spinal reflex vasoconstriction mechanism which is apparent only when the sino-aortic reflexes are intact.
D000818:Animals; D001011:Aorta / Q000294:innervation*; D001783:Blood Flow Velocity; D001794:Blood Pressure; D002346:Carotid Sinus / Q000502:physiology*; D002415:Cats; D003714:Denervation; D007668:Kidney / Q000098:blood supply; D008638:Mesenteric Arteries / Q000502:physiology; D009132:Muscles / Q000098:blood supply; D012018:Reflex; D012890:Sleep / Q000502:physiology*