The effect of topical application of angiotensin on pial arterioles was examined in anesthetized cats equipped with a cranial window for the direct observation of the pial microcirculation of the parietal cortex. Angiotensin in a dose of 0.01 to 1 microgram/ml constricted pial arterioles and arteries strongly. The response of the smaller vessels was greater than that of the larger ones. Intrave...

background: angiotensin converting enzyme (ace) upregulation in stromal cells of joints affected by rheumatoid arthritis may lead to higher tissue angiotensin ii that is a vasoconstrictor and mitogen factor. to date, the role of angiotensin ii on regulating blood flow in inflamed joints has not been studied.   methods: acute and chronic joint inflammation was induced in rabbits by intra-articul...

Pial arteriovenous fistulas (AVFs) of the brain are rare vascular malformations associated with significant risk of hemorrhage and neurological deficits. Depending on their location and high-flow dynamics, these lesions can present treatment challenges for both endovascular and open cerebrovascular surgeons. We present a novel approach to treat intracranial high-flow pial AVFs. A single-channel...

Age-related cerebral blood flow decreases are thought to deteriorate cognition and cause senescence, although the related mechanism is unclear. To investigate the relationships between aging and changes in cerebral blood flow and vasculature, we obtained fluorescence images of young (2-month-old) and old (12-month-old) mice using indocyanine green (ICG). First, we found that the blood flow in o...

Dynamic arterial blood pressures were recorded by micropuncture of 99 cortical surface arteries and arterioles in cats anesthetized with pentobarbital or chloralose and urediane, using the Wiederhielm servocontrolled micropipette pressure system incorporating pipette tips less than 0.5/A in diameter. During these measurements, systemic blood pressure was varied by supplemental intravenous admin...

Dynamic arterial blood pressures were recorded by micropuncture of 99 cortical surface arteries and arterioles in cats anesthetized with pentobarbital or chloralose and urediane, using the Wiederhielm servocontrolled micropipette pressure system incorporating pipette tips less than 0.5/A in diameter. During these measurements, systemic blood pressure was varied by supplemental intravenous admin...

Ammonia intoxication, which results in astrocytic edema and glutamine accumulation, blocks cerebral vasodilation during hypercapnia but not during hypoxia. Ammonia's effect on blood flow during hypocapnia is unclear, with some brain regions showing a paradoxical increase in flow. Here, we studied the responses to hypocapnia of pial arterioles not surrounded by astrocytic end feet to avoid mecha...

Background and Purpose: TA3090 (Clentiazem) has been shown to have cerebrovascular protective properties in three experimental studies. An in vivo investigation was undertaken to determine its effects on pial arteries and cerebral blood flow and its therapeutic value in transient focal cerebral ischemia. Methods: This experiment was divided into two protocols. In the first, 200 or 400 ug/kg per...

The diameters of pial vessels in the cat were measured through a closed cranial window after i.v. injection of dihydralazine (250 microgram or 1 mg x kg-1). The intracranial pressure was recorded from a needle in the cisterna magna. In 7 cats given 1 mg x kg-1 dihydralazine, arterial vessels with a resting diameter of 72 +/- 24 micron (SD) dilated by 58 +/- 21% (p < 0.01), with no significant c...

We report on MR studies of a 15-year-old girl with moyamoya disease in whom diffuse leptomeningeal enhancement ("ivy sign") was revealed by fluid-attenuated inversion-recovery (FLAIR) and contrast-enhanced imaging. We speculate that the mechanism behind this enhancement is caused by a retrograde slow flow of engorged pial vasculature via leptomeningeal anastomosis. Nevertheless, it remains unkn...