Biomaterial Database

The double isotope technique for in vivo determination of the tissue-to-blood partition coefficient for xenon in human subcutaneous adipose tissue--an evaluation. 1985

R Jelnes, and A Astrup, and J Bülow

Local subcutaneous 133xenon (133Xe) elimination was registered in the human forefoot in 34 patients. The tissue/blood partition coefficient for Xe was estimated individually by simultaneous registration of 133Xe and [131I]antipyrine ([131I]AP) washout from the same local depot. When measured in this way, an average partition coefficient for Xe was found to be 4.3 +/- 1.23 ml g-1. This value is significantly lower than the partition coefficient found in a previous in vitro study in which a Xe partition coefficient of 7.5 +/- 1.57 ml g-1 was found. Thus, if the local blood flow is calculated using the partition coefficient found by the double isotope technique, significantly lower values are obtained than if the in vitro determined coefficient is used. This difference is explained mainly by local dilution when injecting xenon subcutaneously. In short-term studies, utilization of the double isotope technique reduces the coefficient of variation on average flow determinations, thus an improvement in accuracy of local blood flow estimation can be obtained compared to the method in which an average partition coefficient is used. For long-term studies a partition coefficient of 7.5 ml g-1 seems valid.

UI	MeSH Term	Description	Entries
D008684	Metatarsus	The part of the foot between the tarsa and the TOES.
D008722	Methods	A series of steps taken in order to conduct research.	Techniques,Methodological Studies,Methodological Study,Procedures,Studies, Methodological,Study, Methodological,Method,Procedure,Technique
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000273	Adipose Tissue	Specialized connective tissue composed of fat cells (ADIPOCYTES). It is the site of stored FATS, usually in the form of TRIGLYCERIDES. In mammals, there are two types of adipose tissue, the WHITE FAT and the BROWN FAT. Their relative distributions vary in different species with most adipose tissue being white.	Fatty Tissue,Body Fat,Fat Pad,Fat Pads,Pad, Fat,Pads, Fat,Tissue, Adipose,Tissue, Fatty
D000983	Antipyrine	An analgesic and antipyretic that has been given by mouth and as ear drops. Antipyrine is often used in testing the effects of other drugs or diseases on drug-metabolizing enzymes in the liver. (From Martindale, The Extra Pharmacopoeia, 30th ed, p29)	Phenazone,Anodynin,Pyramidone
D001157	Arterial Occlusive Diseases	Pathological processes which result in the partial or complete obstruction of ARTERIES. They are characterized by greatly reduced or absence of blood flow through these vessels. They are also known as arterial insufficiency.	Arterial Obstructive Diseases,Arterial Occlusion,Arterial Obstructive Disease,Arterial Occlusions,Arterial Occlusive Disease,Disease, Arterial Obstructive,Disease, Arterial Occlusive,Obstructive Disease, Arterial,Occlusion, Arterial,Occlusive Disease, Arterial
D014980	Xenon Radioisotopes	Unstable isotopes of xenon that decay or disintegrate emitting radiation. Xe atoms with atomic weights 121-123, 125, 127, 133, 135, 137-145 are radioactive xenon isotopes.	Radioisotopes, Xenon