Local control of cerebral blood flow is regulated in part through myogenic constriction of resistance arteries. Although this response requires Ca2+ influx via voltage-dependent Ca2+ channels secondary to smooth muscle cell depolarization, the mechanisms responsible for alteration of vascular smooth muscle (VSM) cell membrane potential are not fully understood. A previous study from our laborat...

Background and objective: The circle of Willis (COW) supports adequate blood supply to the brain. The cardiovascular system, in the current study, is modeled using an equivalent electronic system focusing on the COW.Method: In our previous study we used 42 compartments to model whole car- diovascular system. In the current study, nevertheless, we extended our model by using 63 compartments to m...

Cerebral Atherosclerosis in Japanese. I. Age Related to A therosclerosis • During a period of approximately two years (1965 through 1966), 717 intracranial cerebral arteries (males and females) were obtained from the medicolegal autopsy cases. Systematic grading of the macroscopic severity of cerebral atherosclerosis was performed and the results were reported. In general, cerebral atherosclero...

Exposure to microgravity results in post-flight cardiovascular deconditioning and orthostatic intolerance in astronauts. Vascular oxidative stress injury and mitochondrial dysfunction have been indicated in this process. To elucidate the mechanism for this condition, we investigated whether mitochondria regulated NADPH oxidase in hindlimb unweighting (HU) rat cerebral and mesenteric arteries. F...

The Circle of Willis (CoW) (Figure 1) is a ring-like arterial structure located at the base of the brain. It is the major arterial anastomoses in the brain and is responsible for the distribution of oxygenated blood throughout the cerebral mass. The Internal Carotid (ICA) and Basilar (BA) arteries bring blood into the CoW and are termed afferent arteries. The Anterior (ACA), Middle (MCA), and P...

BACKGROUND AND PURPOSE Cerebral vasospasm after subarachnoid hemorrhage (SAH) is a major contributor to mortality and morbidity after aneurysm rupture. Recently, R-type voltage-dependent Ca(2+) channel (VDCC) expression has been associated with increased cerebral artery constriction in a rabbit model of SAH. The goal of the present study was to examine whether the blood component oxyhemoglobin ...

Phosphodiesterase 5 (PDE5) is associated with migraine pathophysiology, stroke recovery and vasospasm treatment. The potential vascular interplay of PDE5 inhibitors sildenafil, tadalafil and UK-114,542 was studied by intra- versus extra-luminal administration in rat middle cerebral arteries in vitro and on middle meningeal arteries in vivo. By Western blot PDE5 was detected in both cerebral and...

PURPOSE To characterize cerebral hemodynamics in patients immediately before microsurgical resection of moderate to large arteriovenous malformations during isoflurane anesthesia. METHODS In angiographically defined arteriovenous malformation feeding and nonfeeding arteries, transcranial Doppler studies were performed in 25 surgeries on 22 patients. The mean blood flow velocity and pulsatilit...

BACKGROUND AND PURPOSE The transient receptor potential channel TRPM4 is critically linked to the myogenic constrictor response of cerebral arteries that occurs when intravascular pressure increases. This myogenic behavior is thought to be fundamentally involved in the mechanisms of blood flow autoregulation. In this study, we tested the hypothesis that TRPM4 channels in cerebrovascular myocyte...

Pearce, William. Hypoxic regulation of the fetal cerebral circulation. J Appl Physiol 100: 731–738, 2006; doi:10.1152/japplphysiol.00990.2005.—Fetal cerebrovascular responses to acute hypoxia are fundamentally different from those observed in the adult cerebral circulation. The magnitude of hypoxic vasodilatation in the fetal brain increases with postnatal age although fetal cerebrovascular res...