The present study addresses the hypothesis that CO produced from endogenous heme oxygenase (HO) can dilate newborn cerebral arterioles. HO-2 protein was highly expressed in large and small blood vessels, as well as parenchyma, of newborn pig cerebrum. Topically applied CO dose-dependently dilated piglet pial arterioles in vivo over the range 10-11-10-9M (maximal response). CO-induced cerebrovas...

The current understanding of fMRI, regarding its vascular origins, is based on numerous assumptions and theoretical modeling, but little experimental validation exists to support or challenge these models. The known functional properties of cerebral vasculature are limited mainly to the large pial surface and the small capillary level vessels. However, a significant lack of knowledge exists reg...

With sufficient image encoding, high-resolution fMRI studies are limited by the biological point-spread of the hemodynamic signal. The extent of this spread is determined by the local vascular distribution and by the spatial specificity of blood flow regulation, as well as by measurement parameters that (i) alter the relative sensitivity of the acquisition to activation-induced hemodynamic chan...

Orthogonal polarization spectroscopy (OPS) is a technique for taking images to finally characterise microcirculation. Current image analysis algorithms have limitations when applied to image sequences obtained from the liver. We developed an automatic analysis tool which enables detection of liver vessels, measurement of vessel diameters, and determination of blood flow velocities with sparse u...

BACKGROUND Global brain ischemia-reperfusion during propofol anesthesia provokes persistent cerebral pial constriction. Constriction is likely mediated by Rho-kinase. Cerebral vasoconstriction possibly exacerbates ischemic brain injury. Because Y-27632 is a potent Rho-kinase inhibitor, it should be necessary to evaluate its effects on cerebral pial vessels during ischemia-reperfusion period. We...

Shin, Hwa Kyoung, Yung Woo Shin, and Ki Whan Hong. Role of adenosine A2B receptors in vasodilation of rat pial artery and cerebral blood flow autoregulation. Am. J. Physiol. Heart Circ. Physiol. 278: H339–H344, 2000.—This study was aimed to investigate the underlying mechanism of vasodilation induced by the activation of A2B adenosine receptors in relation to cerebral blood flow (CBF) autoregul...

BACKGROUND The functional modulation of blood flow in the brain is critical for brain health and is the basis of contrast in functional magnetic resonance imaging. There is evident coupling between increases in neuronal activity and increases in local blood flow; however, many aspects of this neurovascular coupling remain unexplained by current models. Based on the rapid dilation of distant pia...

22. Yoshida K, Meyer JS, Sakamoto K, Handa J: Autoregulation of cerebral blood flow. Electromagnetic flow measurements during acute hypertension in the monkey. Circ Res 19: 726-738, 1966 23. Haggendal E, Johansson B: On the pathophysiology of the increased cerebrovascular permeability in acute arterial hypertension in cats. Acta Neurol Scand 48: 265-270, 1972 24. Byrom FB: The pathogenesis of h...

Astrocytes can act as intermediaries between neurons and cerebral arterioles to regulate vascular tone in response to neuronal activity. Release of glutamate from presynaptic neurons increases blood flow to match metabolic demands. CO is a gasotransmitter that can be related to neural function and blood flow regulation in the brain. The present study addresses the hypothesis that glutamatergic ...