We used an anesthetized swine model of regionally "stunned" myocardium to determine the effect of stunning on coronary autoregulation and blood flow heterogeneity. In 18 domestic swine, stunning was accomplished by reducing blood flow to the left anterior descending coronary artery (LAD) by approximately 75% of baseline for 15 min and restoring it to normal for 1 hour. We quantified coronary au...

Renal blood flow (RBF) autoregulation is mediated by at least two mechanisms, the fast acting myogenic response (approximately 5 s) and slow acting tubuloglomerular feedback (TGF; approximately 25 s). Previous studies suggest epithelial Na(+) channel (ENaC) family proteins, beta-ENaC in particular, mediate myogenic constriction in isolated renal interlobar arteries. However, it is unknown wheth...

A utoregulation and Hyperemia of Cerebral Blood Flow as Evaluated by Thermal Diffusion • A thermal diffusion flow probe gave a quantitative dynamic recording of cerebral blood flow (CBF) during bleeding and transfusion in experimental animals. Autoregulation was readily demonstrated in nine of 12 animals and was found only with gradual hypotension. After autoregulation was lost, no increase in ...

Dynamic cerebral autoregulation, that is the transient response of cerebral blood flow to changes in arterial blood pressure, is currently assessed using a variety of different time series methods and data collection protocols. In the continuing absence of a gold standard for the study of cerebral autoregulation it is unclear to what extent does the assessment depend on the choice of a computat...

We evaluated the performance of continuous intracerebral microdialysis to indicate the autoregulatory reserve in 36 severely head-injured patients. All patients received standard treatment with intracranial pressure (ICP) monitoring. A microdialysis probe was placed in the frontal cortex anterior to the ICP catheter. Perfusate was collected frequently and extracellular concentration of glutamat...

BACKGROUND Carotid endarterectomy (CEA) is the first-line treatment in severe carotid stenosis to prevent stroke. Because of methodological limitations, the acute impact of CEA on baroreflex function and cerebral autoregulation is not well defined and was therefore investigated by applying a novel algorithm. METHODS AND RESULTS Systemic arterial blood pressure, ECG and respiration during metr...

The effect of hemorrhagic reduction in systemic blood pressure (SBP) to 90 mm Hg for four hours on autoregulation of renal blood flow (RBF), renal function, and renal histology was examined in control rats, one week norepinephrine-induced acute renal failure (NE-ARF) rats with intact renal nerves, and one week NE-ARF rats with prior renal denervation. The results showed that in control rats, he...

The mechanism of autoregulation of renal blood flow was investigated in anesthetized dogs, using either constant-flow or constant-pressure perfusion of the kidney. Prostaglandinlike material in the renal venous blood was assayed hy the blood-bathed organ technique. Compensatory renal vasodilation, induced either by lowering the blood flow or the perfusion pressure, was accompanied by increased ...

Cerebral autoregulation (CA) is the mechanism that allows the brain to maintain a stable blood flow despite changes in blood pressure. Dynamic CA can be quantified based on continuous measurements of systemic mean arterial pressure (MAP) and global cerebral blood flow. Here, we show that dynamic CA can be quantified also from local measurements that are sensitive to the microvasculature. We use...

Autoregulation of renal blood flow (RBF) is an essential function of the renal microcirculation that has been previously shown to be blunted by excessive dietary salt. Endogenous endothelin 1 (ET-1) is increased following a high-salt (HS) diet and contributes to the control of RBF but the differential effects of ET-1 on renal microvessel autoregulation in response to HS remain to be established...