Dynamics of Capillary Perfusion in the Brain

1991 ◽  
Vol 28 (1-3) ◽  
pp. 190-196
Author(s):  
U. Göbel ◽  
H. Theilen ◽  
H. Schröck ◽  
W. Kuschinsky
Keyword(s):  
Capillary Perfusion ◽  
The Brain

Parallel changes of blood flow and heterogeneity of capillary plasma perfusion in rat brains during hypocapnia

1996 ◽  
Vol 270 (4) ◽  
pp. H1441-H1445
Author(s):  
J. Vogel ◽  
R. Abounader ◽  
H. Schrock ◽  
K. Zeller ◽  
R. Duelli ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Coefficient Of Variation ◽  
Blue Dye ◽  
Capillary Perfusion ◽  
Brain Capillary ◽  
Arterial Pco2 ◽  
Transit Times ◽  
The Brain ◽  
Experimental Group

Plasma perfusion patterns were investigated in brain capillaries during decreased cerebral blood flow induced by hyperventilation. Anesthetized rats were decapitated 3-4 s after being given an intravenous bolus injection of Evans blue dye. the measured steep increase of the arterial dye concentration at this moment ensures that different capillary plasma transit times are reflected in different intracapillary dye concentrations. The observed heterogeneity of capillary plasma transit time was expressed as the coefficient of variation (means +/- SD) of the intracapillary dye concentrations. For comparison, cerebral blood flow was determined at comparable PCO2 values in a second experimental group. At arterial PCO2 values between 40 and 25 mmHg, the cerebral blood flow and the coefficient of variation of the intracapillary dye concentration decreased with decreasing PCO2, whereas at PCO2 values <25 mmHg cerebral blood flow and coefficient of variation did not correlate with the arterial PCO2. However, it cannot be excluded that the coefficient of variation of the intracapillary dye concentration increases between 25 and 14 mmHg and decreases between 14 and 10 mmHg. It is concluded that the reduction of cerebral blood flow measured during moderate hypocapnia is paralleled by a decreased heterogeneity of the brain capillary perfusion. During severe hypocapnia this relationship is lost, indicating a potential disturbance of the cerebral microcirculation.

Personality and Regional Cerebral Blood Flow

1984 ◽  
Vol 144 (5) ◽  
pp. 529-532 ◽  
Author(s):  
Roy J. Mathew ◽  
Maxine L. Weinman ◽  
Deborah L. Barr
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Brain Function ◽  
Regional Cerebral Blood Flow ◽  
Cortical Arousal ◽  
Regional Cerebral Blood ◽  
Capillary Perfusion ◽  
Brain Capillary ◽  
Eysenck Personality Inventory ◽  
The Brain

SummaryThe extraversion–introversion dimension of personality is believed to have an inverse relationship with cortical arousal. Brain capillary perfusion is a well established index of brain function and arousal. Regional cerebral blood flow was measured in 51 right-handed females whose personality structure was examined with the Eysenck Personality Inventory (EPI). Significant inverse correlations were found between the brain blood flow and the extraversion–introversion score of EPI.

Capillary perfusion during incomplete forebrain ischemia and reperfusion in rat brain

1993 ◽  
Vol 265 (2) ◽  
pp. H642-H648 ◽  
Author(s):  
H. Theilen ◽  
H. Schrock ◽  
W. Kuschinsky
Keyword(s):  
Rat Brain ◽  
Evans Blue ◽  
Ischemia Reperfusion ◽  
Experimental Models ◽  
Forebrain Ischemia ◽  
Capillary Perfusion ◽  
Experimental Conditions ◽  
Brain Capillary ◽  
Arterial Blood ◽  
The Brain

Previous studies have shown a complete plasma perfusion of all capillaries in the rat brain under normal physiological conditions. This raises the question under which experimental conditions nonperfused capillaries may show up in the brain. Two experimental models were investigated in rats. 1) Reduced cerebral blood flow (CBF) during incomplete forebrain ischemia: hemorrhagic hypotension was maintained for 30 min at a mean arterial blood pressure of 41 mmHg. During the final 5 min of hypotension both carotid arteries were ligated. 2) Reperfusion after incomplete forebrain ischemia: reperfusion lasted for 4 h after either 15 or 30 min of incomplete forebrain ischemia. Under both experimental conditions, the density of the existing as well as the plasma-perfused brain capillary network was quantified using fluorescent double staining. Local CBF was measured during incomplete forebrain ischemia using the quantitative autoradiographic 4-iodo-[N-methyl-14C]antipyrine technique. The results showed a decrease in CBF during incomplete forebrain ischemia, which amounted up to 94%. Whereas normotensive control animals showed a complete staining of all capillaries within 5 s after the intravenous injection of Evans blue, this period of time was increased to 10 s during incomplete forebrain ischemia, indicating a delayed capillary perfusion. Four hours of reperfusion after 15 min of incomplete forebrain ischemia resulted in a complete capillary staining, whereas reperfusion after 30 min of ischemia was followed by intracerebral bleedings and a few nonperfused capillary areas (circulation time of Evans blue: 10 s).(ABSTRACT TRUNCATED AT 250 WORDS)

Determination of capillary perfusion pattern in rat brain by timed plasma labeling

1990 ◽  
Vol 258 (1) ◽  
pp. H80-H84
Author(s):  
F. Vetterlein ◽  
B. Demmerle ◽  
A. Bardosi ◽  
U. Gobel ◽  
G. Schmidt
Keyword(s):  
Fluorescein Isothiocyanate ◽  
Left Heart ◽  
Brain Capillaries ◽  
Capillary Perfusion ◽  
Cranial Window ◽  
Heart Chamber ◽  
S Period ◽  
The Brain ◽  
Infusion Period

The pattern of capillary perfusion was studied in the brain of anesthetized rats. Two plasma labels were used to demonstrate the density of capillaries perfused during a 10-min period [fluorescein isothiocyanate (FITC) globulin], as well as during a 10-, 3-, or 1-s period [lissamine-rhodamine B 200 (RB200) globulin, infused into the left heart chamber], respectively. A special biopsy cutting-freezing system was used to withdraw brain tissue via a cranial window for histological analysis of dye distribution at the end of the infusion period. Complete labeling of all capillaries was already found after 10 s of dye circulation. However, intra-arterial dye infusion for 3 and 1 s led to reduced filling of capillaries: cortex 86.6 +/- 5.2 and 6.8 +/- 1.8%, hippocampus 95.0 +/- 1.6 and 9.9 +/- 2.1%, and thalamus 97.9 +/- 1.0 and 11.7 +/- 1.8%, respectively. The period of 1 s was found to be the circulation time from left heart chamber to brain capillaries. It can thus be concluded that in the studied brain areas greater than 85% of capillaries are reached by a plasma flow within 2 s and that the remaining small fraction completely fills within 10 s.

Effect of acetazolamide on cerebral blood flow and capillary patency

1992 ◽  
Vol 73 (5) ◽  
pp. 1756-1761 ◽  
Author(s):  
H. M. Frankel ◽  
E. Garcia ◽  
F. Malik ◽  
J. K. Weiss ◽  
H. R. Weiss
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Blood Gases ◽  
Capillary Perfusion ◽  
Arterial Pco2 ◽  
Arterial Blood ◽  
Cerebral Capillary ◽  
The Brain

This study investigated the effects 2 h after administration of acetazolamide on cerebral blood flow and the pattern of cerebral capillary perfusion. Arterial blood pressure, heart rate, arterial blood gases, and pH were recorded in two groups of rats along with either regional cerebral blood flow or the percentage of capillary volume per cubic millimeter and number per square millimeter perfused as determined in cortical, thalamic, pontine, and medullary regions of the brain. Blood pressure, heart rate, and arterial PCO2 were not significantly different between the rats receiving acetazolamide (100 mg/kg) and the controls. Arterial blood pH was significantly lower in the acetazolamide rats. Blood flow increased significantly in the cortical (+ 102%), thalamic (+ 89%), and pontine (+ 88%) regions receiving acetazolamide. In control rats, approximately 60% of the capillaries were perfused in all of the examined regions. The percentage of capillaries per square millimeter perfused was significantly greater in the cortical (+ 52%), thalamic (+ 49%), and pontine (+ 47%) regions of acetazolamide rats compared with controls. In the medulla the increases in blood flow and percentage of capillaries perfused were not significant. Thus in the regions that acetazolamide increased cerebral blood flow, it also increased the percentage of capillaries perfused.

Effects of Acupuncture on Tissue-Oxygenation of the Rat Brain

1977 ◽  
Vol 05 (02) ◽  
pp. 147-154 ◽  
Author(s):  
Gregory S. Chen ◽  
Wilhelm Erdmann
Keyword(s):  
Rat Brain ◽  
Brain Tissue ◽  
Tissue Oxygenation ◽  
Perfusion Pressure ◽  
Tissue Perfusion ◽  
Albino Rats ◽  
Capillary Perfusion ◽  
Unconscious Patients ◽  
The Brain ◽  
Inspiratory Oxygen

Acupuncture has been claimed to be effective in restoring consciousness in some comatose patients. Possible mechanisms to explain alleged acupuncture-induced arousal may include vasodilatory effects caused by sympathetic stimulation which leads to an augmentation of cerebral microcirculation and thereby improves oxygen supply to the brain tissue. Experiments were performed in ten albino rats (Wistar) employing PO 2 microelectrodes which were inserted into the cortex of the animals through small burholes. Brain tissue PO 2 was continuously recorded before, during, and after acupuncture. Stimulation of certain acupuncture loci (Go-26) resulted in immediate increase of PO 2 in the frontal cortex of the rat brain. This effect was reproducible. The effect was comparable to that obtained with increase of inspiratory CO 2 known to induce arterial vasodilatation and thus capillary perfusion pressure. The effect was more significant as compared to tissue PO 2 increases obtained after increase of inspiratory oxygen concentration from 21% to 100%. It appears that acupuncture causes an increase of brain tissue perfusion which may be, at least in part, responsible for arousal of unconscious patients. Dilatation of cerebral vascular vessels and improvement of autoregulation in the brain by acupuncture stimulation may also explain the effectiveness of acupuncture in the treatment of migraine headache.

Inhomogeneity of Local Capillary Perfusion in the Brain

2015 ◽  
pp. 49-60
Author(s):  
W. Kuschinsky ◽  
B. Klein ◽  
H. Schr�ck ◽  
F. Vetterlein
Keyword(s):  
Capillary Perfusion ◽  
The Brain

Cerebral regional capillary perfusion and blood flow after carbon monoxide exposure

1991 ◽  
Vol 71 (4) ◽  
pp. 1196-1200 ◽  
Author(s):  
A. K. Sinha ◽  
J. Klein ◽  
P. Schultze ◽  
J. Weiss ◽  
H. R. Weiss
Keyword(s):  
Blood Flow ◽  
Volume Fraction ◽  
Fluorescein Isothiocyanate ◽  
Regional Cerebral Blood ◽  
Capillary Perfusion ◽  
Brain Vasculature ◽  
Before And After ◽  
Intercapillary Distance ◽  
Lower Brain Stem ◽  
The Brain

Alterations in regional cerebral blood flow (rCBF) and percent perfused capillaries (indicative of functional intercapillary distance) were determined in conscious male Long-Evans rats after reducing their blood O2-carrying capacity by exposing them to 1% CO for 12 min. rCBF was determined by the iodoantipyrine method. rCBF increased from a mean of 106 +/- 8 (SE) ml.min-1.100 g-1 before CO exposure to 173 +/- 14 ml.min-1.100 g-1 after CO exposure. There was a greater flow increase (126%) in the cerebral cortex than in the lower brain stem [pons (45%), medulla (39%)]. Presence of fluorescein isothiocyanate-labeled dextran identified the perfused capillaries before and after CO exposure. The volume fraction (Vv) and number/mm2 (Na) of all capillaries (perfused and nonperfused) in a given area of brain were determined after staining for alkaline phosphatase. The percent Vv and percent Na of perfused capillaries increased uniformly (from approximately 50% to approximately 80%) in all parts of the brain after CO exposure. In the presence of tissue hypoxia with undiminished plasma PO2, the brain vasculature allowed greater flow of blood while the microvasculature adjusted to reduce the diffusion distance for O2.

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