Determination of rat cerebral cortical blood volume changes by capillary mean transit time analysis during hypoxia, hypercapnia and hyperventilation

doi:10.1016/0006-8993(88)90816-5

Brain Research

Volume 454, Issues 1–2, 28 June 1988, Pages 170-178

https://doi.org/10.1016/0006-8993(88)90816-5 Get rights and content

Abstract

Changes in cerebral blood volume due to augmented or diminished numbers of blood-perfused capillaries can be studied in small animals by optical methods. Capillary mean transit time was determined by detection of the passage of a hemodilution bolus through a region of the parietal cerebral cortical surface, using a reflectance spectrophotometer through a small craniotomy in chloral hydrate-anesthetized rats. Local cerebral blood flow was determined in the same region by the butanol indicator-fractionation method. Blood volume was calculated from the product of blood flow and transit time. Normoxic, normocapnic values for these variables wereblood flow= 144ml/100g/min; meantransit time= 1.41s; andblood volume= 3.4ml/100g. Mean transit time reached a minimum (1.1 s) with moderate hypoxia or hypercapnia. Combined hypoxia and hypercapnia did not result in any further decrease in mean transit time although blood flow was much higher than either hypoxia or hypercapnia alone. The maximum blood volume recorded during hypercapnic hypoxia (12.1 ml/100 g) was 3.6 times greater than that at normoxic normocapnia, which suggests that under control conditions in the anesthetized rat considerably less than 100% of the cerebral capillaries were actively perfusing the tissue. These studies demonstrate that optical methods can be used to quantitatively measure blood volume. The data suggest that capillary recruitment is a physiologically significant phenomenon in rat cerebral cortex.

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Determination of rat cerebral cortical blood volume changes by capillary mean transit time analysis during hypoxia, hypercapnia and hyperventilation

Abstract

Brain Research

Math. Biosci.

Microvasc. Res.

Brain Res. Rev.

Brain Research

Brain Research

Math. Biosci.

The blood-brain barrier

Circ. Res.

Infra-red technique for cerebral blood flow: comparison with133Xenon clearance

Neurol. Res.

Reflectometric mapping of microregional blood flow and blood volume in the brain cortex

J. Cereb. Blood Flow Metab.

Induced hemodilution detected by reflectometry for measuring microregional blood flow and blood volume in cat brain cortex

Am. J. Physiol.

The effect of O2 and CO2 on Prostaglandin levels in the cat cerebral cortex

Circ. Res.

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J. Appl. Physiol.

The nitrous oxide method for the quantitative determination of cerebral blood flow in man: theory, procedure, and normal values

J. Clin. Invest.

Applied Regression Analysis and Other Multivariable Methods

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J. Neurosurg.

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The effect of O₂ and CO₂ on Prostaglandin levels in the cat cerebral cortex