The effect of acute arterial baroreflex dysfunction on cerebral autoregulation (CA) in otherwise healthy @entity1 is unknown. We identified dynamic CA with and without arterial baroreflex-mediated @entity591 and consequent changes in cardiac output during acute @entity551 whilst continuously monitoring changes in middle cerebral artery mean blood velocity (MCA V(mean)). Acute @entity551 was induced in nine healthy subjects (mean +/- s.d.; 26 +/- 3 years) by releasing bilateral thigh cuffs after 6 min of supra-systolic resting ischaemia. @entity551 was induced before and after sympathetic blockade ( @entity8652 receptors), and combined sympathetic-cholinergic blockade. That sequential bolus injections of @entity1854 (50 microg), followed 60 s later by @entity2647 (50 microg), elicited < 5 beats min(-1) change in heart rate was verified to confirm that full cardiac autonomic blockade was achieved. Thigh cuff release elicited a transient drop in mean arterial pressure and resultant @entity591 . This tachycardic response was diminished in full cardiac blockade (vs. control, P = 0.029; vs. @entity8652 adrenergic blockade, P = 0.031). Dynamic CA was also attenuated in the full blockade condition compared to both control (P = 0.028) and @entity8652 adrenergic blockade conditions (P = 0.015), and was related with the @entity591 response (P = 0.015). These data indicate an important role of the cardiac baroreflex in dynamic CA.

Influence of baroreflex-mediated @entity591 on the regulation of dynamic cerebral perfusion during acute @entity551 in XXXX .

@entity1 :: ('9606', 'Species') :: ['humans'] @entity8652 :: ('3779', 'Gene') :: ['beta-1'] @entity1854 :: ('MESH:D009599', 'Chemical') :: ['sodium nitroprusside'] @entity591 :: ('MESH:D013610', 'Disease') :: ['attenuated tachycardia', 'tachycardia'] @entity2647 :: ('MESH:D010656', 'Chemical') :: ['phenylephrine hydrochloride'] @entity551 :: ('MESH:D007022', 'Disease') :: ['Hypotension', 'hypotension']
@entity1 :: (9606,Species) :: ['humans']
