Distribution of Oxygen Partial Pressure and Cerebral Blood Vessels in Rat Cerebral Cortex

2002 ◽  
Vol 2002.14 (0) ◽  
pp. 131-132
Author(s):  
Kazuto MASAMOTO ◽  
Tomoko NEGISHI ◽  
Takayoshi KURACHI ◽  
Naosada TAKIZAWA ◽  
Hirosuke KOBAYASHI ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Blood Vessels ◽  
Rat Cerebral Cortex ◽  
Cerebral Blood Vessels

Evidence that heterogeneity of cerebral blood flow does not involve vascular recruitment

1993 ◽  
Vol 264 (5) ◽  
pp. H1740-H1743 ◽  
Author(s):  
J. L. Williams ◽  
M. Shea ◽  
S. C. Jones
Keyword(s):  
Blood Flow ◽  
Image Analysis ◽  
Cerebral Cortex ◽  
Cerebral Blood Flow ◽  
Blood Vessels ◽  
Temporal Heterogeneity ◽  
Cerebral Blood Vessels ◽  
Fluorescent Tracers ◽  
Spatial And Temporal Heterogeneity ◽  
Large Vessels

Recent studies indicate that blood flow to cerebral cortex is not homogeneous but may vary both spatially and temporally. In addition, some investigators have reported that capillaries and arterioles can be recruited to increase cerebral blood flow, an issue that is extremely controversial. The goal of this study was to determine whether recruitment of cerebral blood vessels is an important mechanism in spatial and temporal heterogeneity of cerebral blood flow. In seven anesthetized ventilated rats, different fluorescent tracers were injected 45 and 10 s before decapitation. In addition, [14C]iodoantipyrine also was injected 10 s before decapitation. After the brains were sectioned, fields in the cerebral cortex were examined microscopically for fluorescence and processed for measurement of cerebral blood flow with techniques of quantitative autoradiography and image analysis. With examination of 24 +/- 2 (SE) points in cerebral cortex of each rat, similar numbers of small blood vessels (< or = 10 microns) were counted that contained fluorescent tracers injected 45 and 10 s before decapitation (346 +/- 48 and 355 +/- 42 vessels/mm2, respectively; P > 0.05). Large blood vessels (20-60 microns; 73 +/- 6 vessels in each rat) contained both fluorescent tracers. In addition, adjacent regions of high and low blood flow contained similar numbers of small and large vessels. Our findings indicate that vascular recruitment is not an important mechanism in temporal or spatial heterogeneity of cerebral blood flow.

scholarly journals Distribution of Nitric Oxide Synthase in the Human Cerebral Blood Vessels and Brain Tissues

1994 ◽  
Vol 14 (6) ◽  
pp. 930-938 ◽  
Author(s):  
Hidekazu Tomimoto ◽  
Masaki Nishimura ◽  
Toshihiko Suenaga ◽  
Sinichi Nakamura ◽  
Ichiro Akiguchi ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Cerebral Cortex ◽  
Nitric Oxide Synthase ◽  
Blood Vessels ◽  
Nadph Diaphorase ◽  
Type I ◽  
Type Ii ◽  
Cerebral Blood Vessels ◽  
Oxide Synthase

The distribution of nitric oxide synthase was investigated in human cerebral blood vessels and brain tissues. NADPH-diaphorase histochemistry, which is a marker for nitric oxide synthase in neurons and endothelial cells, revealed periadventitial nerve fibers in the arteries of the circle of Willis and their cortical branches, as well as the common carotid and subclavian arteries. The fibers were mostly nonvaricose in the periadventitial nerve trunk and were varicose within the adventitia. Patchy reaction products were distributed in the perinuclear region of each endothelial cell. Smooth muscle cells in the tunica media were weakly stained. Staining was particularly intense in regions with atherosclerotic changes, which consist of macrophage infiltration and proliferation of fibroblasts. In the neural parenchyma, two types of NADPH-diaphorase reactive neurons were differentiated. Type I neurons were intensely stained, medium-sized, and bipolar or multipolar. They were distributed in the cerebral cortex and white matter, mostly in the subcortical white matter. Type II neurons were lightly stained, small oval neurons with fine processes and were distributed in the cerebral cortex. Endothelial cells were intensely reactive for NADPH-diaphorase in the arteries, arterioles, and capillaries but weakly in veins. Immuno-histochemistry for neural nitric oxide synthase labeled perivascular nerves in the larger arteries and those in the neural parenchyma. Both type I and type II neurons were labeled. Nitric oxide synthase in endothelial cells and the nerve encircling blood vessels further suggests a dual control of cerebral circulation by nitric oxide in human brain.

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