Biomaterial Database

Fetal whole-body permeability--surface area product and reflection coefficient for plasma proteins. 1988

P S Gold, and R A Brace

Division of Perinatal Biology, Loma Linda University, California 92350.

The transcapillary distribution of protein between the vascular and interstitial spaces largely depends on the protein permeability characteristics of the capillary membranes, i.e., the reflection coefficient and permeability - surface area product for plasma proteins. Our purpose was to estimate whole-body values for these parameters in chronically catheterized, near-term fetal sheep. Average experimental changes in plasma protein concentration, blood volume and vascular pressures following fetal hemorrhage or intravascular saline infusion were analyzed using mathematical modeling and parameter optimization techniques. The mathematical model consisted of three interacting compartments: (1) fetal blood, (2) fetal interstitium, and (3) maternal blood. We found that the mean fetal whole-body protein reflection coefficient averaged 0.61 following hemorrhage and 0.80 after intravascular saline infusions. The protein permeability - surface area product averaged 0.36 ml/min/kg for the hemorrhages and 0.70 ml/min/kg following saline infusions. The major findings are that the fetus has (1) a permeability - surface area product averaging 15 times that of the adult, (2) a protein reflection coefficient approximately 70 to 90% of adult values, and (3) the ability to decrease its capillary surface area following hemorrhage.

UI	MeSH Term	Description	Entries
D008955	Models, Cardiovascular	Theoretical representations that simulate the behavior or activity of the cardiovascular system, processes, or phenomena; includes the use of mathematical equations, computers and other electronic equipment.	Cardiovascular Model,Cardiovascular Models,Model, Cardiovascular
D001798	Blood Proteins	Proteins that are present in blood serum, including SERUM ALBUMIN; BLOOD COAGULATION FACTORS; and many other types of proteins.	Blood Protein,Plasma Protein,Plasma Proteins,Serum Protein,Serum Proteins,Protein, Blood,Protein, Plasma,Protein, Serum,Proteins, Blood,Proteins, Plasma,Proteins, Serum
D001810	Blood Volume	Volume of circulating BLOOD. It is the sum of the PLASMA VOLUME and ERYTHROCYTE VOLUME.	Blood Volumes,Volume, Blood,Volumes, Blood
D002196	Capillaries	The minute vessels that connect arterioles and venules.	Capillary Beds,Sinusoidal Beds,Sinusoids,Bed, Sinusoidal,Beds, Sinusoidal,Capillary,Capillary Bed,Sinusoid,Sinusoidal Bed
D002199	Capillary Permeability	The property of blood capillary ENDOTHELIUM that allows for the selective exchange of substances between the blood and surrounding tissues and through membranous barriers such as the BLOOD-AIR BARRIER; BLOOD-AQUEOUS BARRIER; BLOOD-BRAIN BARRIER; BLOOD-NERVE BARRIER; BLOOD-RETINAL BARRIER; and BLOOD-TESTIS BARRIER. Small lipid-soluble molecules such as carbon dioxide and oxygen move freely by diffusion. Water and water-soluble molecules cannot pass through the endothelial walls and are dependent on microscopic pores. These pores show narrow areas (TIGHT JUNCTIONS) which may limit large molecule movement.	Microvascular Permeability,Permeability, Capillary,Permeability, Microvascular,Vascular Permeability,Capillary Permeabilities,Microvascular Permeabilities,Permeabilities, Capillary,Permeabilities, Microvascular,Permeabilities, Vascular,Permeability, Vascular,Vascular Permeabilities
D003198	Computer Simulation	Computer-based representation of physical systems and phenomena such as chemical processes.	Computational Modeling,Computational Modelling,Computer Models,In silico Modeling,In silico Models,In silico Simulation,Models, Computer,Computerized Models,Computer Model,Computer Simulations,Computerized Model,In silico Model,Model, Computer,Model, Computerized,Model, In silico,Modeling, Computational,Modeling, In silico,Modelling, Computational,Simulation, Computer,Simulation, In silico,Simulations, Computer
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
D012756	Sheep	Any of the ruminant mammals with curved horns in the genus Ovis, family Bovidae. They possess lachrymal grooves and interdigital glands, which are absent in GOATS.	Ovis,Sheep, Dall,Dall Sheep,Ovis dalli