Biomaterial Database

Hydrogen clearance method for determining local cerebral blood flow. II. Effect of heterogeneity in cerebral blood flow. 1986

R von Kummer, and F von Kries, and S Herold

The time course of hydrogen uptake and washout was followed simultaneously in extracranial arterial blood, cortex, subcortical white matter, and caudate nucleus of the cat brain to study intercompartmental hydrogen concentration differences. A clear delay of 1-2 min was seen between the onsets of concentration increase in arterial blood and low-flow brain tissues. Equilibration time was dependent on local CBF and varied between 3 and 34 min. Hydrogen was not cleared simultaneously from the regions under detection. This led to considerable concentration differences within the cerebral tissue during washin and washout phases. Analysis of the clearance curves revealed that secondary equilibration occurs during washout. Hydrogen concentration in the external carotid artery was not a reliable reflection of tracer input in the brain tissues. The consequences of these observations for other techniques of CBF measurement using less diffusive gases and external detection are discussed.

UI	MeSH Term	Description	Entries
D012039	Regional Blood Flow	The flow of BLOOD through or around an organ or region of the body.	Blood Flow, Regional,Blood Flows, Regional,Flow, Regional Blood,Flows, Regional Blood,Regional Blood Flows
D001825	Body Fluid Compartments	The two types of spaces between which water and other body fluids are distributed: extracellular and intracellular.	Body Fluid Compartment,Compartment, Body Fluid,Compartments, Body Fluid,Fluid Compartment, Body,Fluid Compartments, Body
D002342	Carotid Artery, External	Branch of the common carotid artery which supplies the exterior of the head, the face, and the greater part of the neck.	Arteries, External Carotid,Artery, External Carotid,Carotid Arteries, External,External Carotid Arteries,External Carotid Artery
D002415	Cats	The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)	Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
D002421	Caudate Nucleus	Elongated gray mass of the neostriatum located adjacent to the lateral ventricle of the brain.	Caudatus,Nucleus Caudatus,Caudatus, Nucleus,Nucleus, Caudate
D002540	Cerebral Cortex	The thin layer of GRAY MATTER on the surface of the CEREBRAL HEMISPHERES that develops from the TELENCEPHALON and folds into gyri and sulci. It reaches its highest development in humans and is responsible for intellectual faculties and higher mental functions.	Allocortex,Archipallium,Cortex Cerebri,Cortical Plate,Paleocortex,Periallocortex,Allocortices,Archipalliums,Cerebral Cortices,Cortex Cerebrus,Cortex, Cerebral,Cortical Plates,Paleocortices,Periallocortices,Plate, Cortical
D002560	Cerebrovascular Circulation	The circulation of blood through the BLOOD VESSELS of the BRAIN.	Brain Blood Flow,Regional Cerebral Blood Flow,Cerebral Blood Flow,Cerebral Circulation,Cerebral Perfusion Pressure,Circulation, Cerebrovascular,Blood Flow, Brain,Blood Flow, Cerebral,Brain Blood Flows,Cerebral Blood Flows,Cerebral Circulations,Cerebral Perfusion Pressures,Circulation, Cerebral,Flow, Brain Blood,Flow, Cerebral Blood,Perfusion Pressure, Cerebral,Pressure, Cerebral Perfusion
D006859	Hydrogen	The first chemical element in the periodic table with atomic symbol H, and atomic number 1. Protium (atomic weight 1) is by far the most common hydrogen isotope. Hydrogen also exists as the stable isotope DEUTERIUM (atomic weight 2) and the radioactive isotope TRITIUM (atomic weight 3). Hydrogen forms into a diatomic molecule at room temperature and appears as a highly flammable colorless and odorless gas.	Protium,Hydrogen-1
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor