&AINSBY, WENDELL N. Azltoregulation of blood flow in skeletal muscle during increased metabolic activity. Am. J. Physiol. 202(2) : 273-276. 1962. -The effect of increased metabolic rate on autoregulation of blood flow in skeletal muscle was investigated by stimulating muscle to contract. At elevated metabolic rates good autoregulation of blood flow was observed but at higher blood flow levels t...

The exact spatial distribution of impaired cerebral autoregulation in carotid artery disease is unknown. In this pilot study, we present a new approach of multichannel near-infrared spectroscopy (mcNIRS) for non-invasive spatial mapping of dynamic autoregulation in carotid artery disease. In 15 patients with unilateral severe carotid artery stenosis or occlusion, cortical hemodynamics in the bi...

BACKGROUND AND PURPOSE Prior work aimed at improving our understanding of human cerebral autoregulation has explored individual physiological mechanisms of autoregulation in isolation, but none has attempted to consolidate the individual roles of these mechanisms into a comprehensive model of the overall cerebral pressure-flow relationship. METHODS We retrospectively analyzed this relationshi...

• The genesis of intrinsic vascular smooth muscle activity and its role in the local control of tissue blood flow has been the source of considerable controversy, particularly in regard to the mechanism underlying autoregulation of blood flow. The phenomenon of autoregulation has been reported for several vascular beds including kidney, intestine,' 4 brain, and heart. A number of investigators ...

Stroke Patients To the Editor: We have read with interest the article by Georgiadis et al in the December 2002 issue of Stroke.1 The authors have attempted to examine the integrity of cerebral autoregulation in hypothermic stroke patients. We would like to raise 2 methodological issues. Despite measuring intracranial pressure, the authors have used mean arterial pressure rather than cerebral pe...

Endothelial dysfunction in ischemic acute renal failure (IARF) has been attributed to both direct endothelial injury and to altered endothelial nitric oxide synthase (eNOS) activity, with either maximal upregulation of eNOS or inhibition of eNOS by excess nitric oxide (NO) derived from iNOS. We investigated renal endothelial dysfunction in kidneys from Sprague-Dawley rats by assessing autoregul...

BACKGROUND AND PURPOSE In patients with stroke and long-standing hypertension, the autoregulation curve of cerebral blood flow (CBF) shifts toward higher blood pressure levels. Angiotensin-converting enzyme (ACE) inhibitors reduce blood pressure and shift the autoregulation curve back to normal in hypertensive patients. ACE inhibitors have 2 major pharmacological properties: they inhibit both t...

Cerebral blood flow is maintained constant over a range of cerebral perfusion pressures by cerebral autoregulation. Impaired cerebral autoregulation may be important in the pathogenesis of cerebral ischaemia. The mechanisms mediating normal cerebral autoregulation in humans are poorly understood. We used a recently described transcranial Doppler technique, which allows non-invasive measurement ...

BACKGROUND AND PURPOSE Clinical application of continuous autoregulation monitoring would benefit from a comparison of curves generated by online monitoring with standard autoregulation curves in animal models. We characterized the accuracy of 3 continuous monitors of autoregulation in a piglet model of hypotension. METHODS Piglets 5 to10 days old with intracranial pressure (ICP) at naïve or ...