introduction:adenosine as a potent vasodilator has physiological role in regulation of regional cerebral blood flow (rcbf). metod: laser-dِoppler flowmetry technique was used to study pial vessels blood flow responses to adenosine receptors agonists and antagonist. male sprague dawley rats (250-350g) that were housed in standard conditions, were anesthetized with urethane (1.5g/kg). adenosine (g...

Introduction:Adenosine as a potent vasodilator has physiological role in regulation of regional cerebral blood flow (rCBF). Metod: Laser-Dِoppler flowmetry technique was used to study pial vessels blood flow responses to adenosine receptors agonists and antagonist. Male Sprague Dawley rats (250-350g) that were housed in standard conditions, were anesthetized with Urethane (1.5g/kg). Adenosine ...

Due to methodologic difficulties, few investigations have been made on the blood flow velocity in the cerebral microcirculation. Using a newly developed video camera method, we simultaneously measured the blood flow velocity and diameter of pial arteries during hemorrhagic hypotension, after blood pressure recovery, and during CO2 inhalation in cats. When the mean arterial blood pressure was lo...

In the weeks following birth, both the brain and the vascular network that supplies it undergo dramatic alteration. While studies of the postnatal evolution of the pial vasculature and blood flow through its vessels have been previously done histologically or acutely, here we describe a neonatal reinforced thin-skull preparation for longitudinally imaging the development of the pial vasculature...

Response to Letter Regarding Article, “Relative Contributions of Sympathetic, Cholinergic, and Myogenic Mechanisms to Cerebral Autoregulation” We thank Dr Shang for his interest in our study. We assessed cerebral autoregulation based on the relation between fluctuations in arterial pressure and those in middle cerebral artery blood flow before and after pharmacological blockade of 3 proposed me...

Our goal was to determine whether sympathetic stimulation during acute hypertension constricts large cerebral arteries and attenuates increases in cerebral microvascular pressure. We measured cerebral blood flow with microspheres and pressure in small pial arteries with a servonull device in anesthetized cats. During moderate hypertension, sympathetic stimulation had little effect on resistance...

In lightly anesthetized cats, the left middle cerebral artery was occluded using a transorbital approach. Pial arterial pressure was measured with a feedback-controlled micropressure recording system in the territory of the occluded artery, and compared with changes of cortical blood flow, cortical steady potential and cortical EEG activity. After middle cerebral artery occlusion pial artery pr...

The goal of this study was to determine whether responses of cerebral vessels to intravascular administration of serotonin are altered in stroke-prone spontaneously hypertensive rats. We measured pressure in pial arterioles and cerebral blood flow in normotensive and hypertensive rats during intra-atrial infusion of serotonin. In normotensive rats, pial arteriolar pressure was 48 +/- 3 mm Hg (m...

A systematic analysis of the possible existence of neurogenic control of precapillary pial vessels was made in three species (cat, dog, and rabbit). In all of these animals, pial vessels failed to respond to externally applied isoproterenol or norepinephrine in high concentrations (up to 100 fig/ml), although the vessels did dilate in response to externally applied histamine. Adrenergic nerve e...

A systematic analysis of the possible existence of neurogenic control of precapillary pial vessels was made in three species (cat, dog, and rabbit). In all of these animals, pial vessels failed to respond to externally applied isoproterenol or norepinephrine in high concentrations (up to 100 fig/ml), although the vessels did dilate in response to externally applied histamine. Adrenergic nerve e...