The effect of chronic renovascular hypertension on the autoregulation of cerebral blood flow was studied in anesthetized baboons. Cerebral blood flow was measured by the intracarotid 133Xe clearance method. Six baboons with renal hypertension of 8-12 weeks' duration were compared with six normotensive controls. The lower limit of autoregulation was determined following controlled hemorrhage. In...

To determine the effect of perfluorocarbon (PFC) hemodilution on myocardial vessel capacity to autoregulate, circumflex coronary artery pressure-flow relations were studied in anesthetized dogs under three conditions: maximal vasodilatation before and after PFC; autoregulation before and after PFC with 100% oxygen supplemented with room air ventilation, and autoregulation with PFC hemodilution ...

In recent years, the feasibility of near-infrared spectroscopy to continuously assess cerebral autoregulation has gained increasing interest. By plotting cerebral oxygen saturation over blood pressure, clinicians can generate an index of autoregulation: the cerebral oximetry index (COx). Successful integration of this monitoring ability in daily critical care may allow clinicians to tailor bloo...

References 1. Newell DW, Aaslid R, Lam A, Mayberg T, Winn HR. Flow and velocity during autoregulation testing in humans. Stroke. 1994; 25:270. Abstract. 2. Miiller HR, Casty M, Moll R, Zehnder R. Response of middle cerebral artery volume flow. Cerebrovasc Dis. 1991;l:82-89. 3. Muller HR, Casty M, Loeb J, Haefele M, Boccalini P. Transcranial Doppler sonography under lower body negative pressure ...

Posterior reversible encephalopathy syndrome (PRES) is a neurological disorder characterized by its reversibility both radiologically and clinically, it typically has favorable prognosis. Its etiopathogenesis not clear, although known that involves endothelial dysfunction of the posterior cerebral vasculature, leading to failed autoregulation. We report patient with PRES may have been caused an...

Effects of BetaAdrenergic Blockade on Cerebral A utoregulalion and Chemical Vasomotor Control in Patients With Stroke • Autoregulation and chemical vasomotor control of cerebral blood flow (CBF) were measured in 14 patients with cerebral ischemia and infarction classified according to severity and anatomical location before and after intracarotid injection of the beta-adrenergic blocking agent,...

This study examined the effect of changing hindlimb metabolic rate on hindlimb blood flow control in anesthetized dogs. The hyperemias induced by graded levels of arterial hypoxia and the degree of steady state autoregulation evoked by changes in blood pressure were measured. Metabolic rate was increased above the resting value by direct electrical stimulation of hindlimb muscles at rates from ...

Flow of tubule fluid to the macula densa is part of a proposed feedback loop for autoregulation of glomerular filtration rate. In the present study, autoregulation of single nephron filtration rate was tested in the presence and the absence of flow to the macula densa in the rat. Filtration rates were measured at elevated arterial blood pressures caused by carotid occlusion and vagal section an...

Impairments of autoregulation and neurovascular coupling in the optic nerve head play a critical role in ocular pathologies, especially glaucomatous optic neuropathy. We critically review the literature in the field, integrating results obtained in clinical, experimental, and theoretical studies. We address the mechanisms of autoregulation and neurovascular coupling in the optic nerve head, the...