32 Cerebral autoregulation adjusts cerebrovascular resistance in the face of changing 33 perfusion pressures to maintain relatively constant flow. Results from several studies 34 suggest that cardiac output may also play a role. We tested the hypothesis that cerebral 35 blood flow would autoregulate independent of changes in cardiac output. Transient 36 systemic hypotension was induced by thigh...

More than 29 million of Americans have diabetes. About 30–40% of the diabetic patients will eventually develop diabetic nephropathy (DN), which is the leading cause of end-stage renal disease (Centers for Disease Control and Prevention, 2014; United States Renal Data System., 2012). Control of blood pressure (BP) and blood glucose has been shown to reduce the risk of developing DN (Nathan 2014)...

The autoregulation of blood flow, the maintenance of almost constant blood flow in the face of variations in arterial pressure, is characteristic of many tissue types. Here, contributions to the autoregulation of pressure-dependent, shear stress-dependent, and metabolic vasoactive responses are analyzed using a theoretical model. Seven segments, connected in series, represent classes of vessels...

BACKGROUND AND PURPOSE Impaired cerebral autoregulation (CA) from high-altitude hypoxia may cause high-altitude cerebral edema in newcomers to a higher altitude. Furthermore, it is assumed that high-altitude natives have preserved CA. However, cerebral autoregulation has not been studied at altitude. METHODS We studied CA in 10 subjects at sea level and in 9 Sherpas and 10 newcomers at an alt...

Autoregulation is critical for protecting the kidney against arterial pressure elevation and is compromised in some forms of hypertension. Evidence indicates that activated lymphocytes contribute importantly to cardiovascular injury in hypertension. We hypothesized that activated lymphocytes contribute to renal vascular dysfunction by impairing autoregulation and P2X(1) receptor signaling in AN...

introduction : cerebral autoregulation (ca) and mean cerebral blood flow velocity in males and females are still under controversy. the present study was scheduled to address the effect of sex on these parameters. materials and methods : the present study was interventional and performed on 30 healthy volunteers (15 males aging from 20-30 yrs and mean age of 23.9±3 years old and 15 females agin...

BACKGROUND AND PURPOSE Individualizing mean arterial blood pressure targets to a patient's cerebral blood flow autoregulatory range might prevent brain ischemia for patients undergoing cardiopulmonary bypass (CPB). This study compares the accuracy of real-time cerebral blood flow autoregulation monitoring using near-infrared spectroscopy with that of transcranial Doppler. METHODS Sixty adult ...

We examined the effect of positive autoregulation on the steady-state behavior of the PhoQ/PhoP two-component signaling system in Escherichia coli. We found that autoregulation has no effect on the steady-state output for a large range of input stimulus, which was modulated by varying the concentration of magnesium in the growth medium. We provide an explanation for this finding with a simple m...

Myogenic response, a phenomenon in which resistance size arteries and arterioles swiftly constrict or dilate in response to an acute elevation or reduction, respectively, in intravascular pressure is a key component of renal autoregulation mechanisms. Although it is well established that the renal system is functionally immature in neonates, mechanisms that regulate neonatal renal blood flow (R...

OBJECTIVE This study tested the hypothesis that overproduction of endogenous nitric oxide (NO) during endotoxemia may modulate coronary autoregulation and myocardial reactive hyperemia. METHODS Hearts of endotoxin-pretreated rats and controls were isolated and arranged for perfusion in a Langendorff preparation. Autoregulation was studied by examining flow-pressure relations during stepwise c...