Estimation of the rate of Ca/sup 2 +/ influx in perfused rat liver using the multiple indicator dilution technique
The multiple indicator dilution technique provides a useful mechanism for the determination of the rates of processes involved in the uptake and subsequent release of substances between an organ, such as the liver, and the vasculature. They have used this technique to investigate the uptake of /sup 45/Ca/sup 2 +/ into the perfused rat liver at a number of different perfusate Ca/sup 2 +/ concentrations. Each perfused liver is calibrated using reference injections of a mixture of /sup 3/H-sucrose and /sup 14/C-urea to determine parameters of a microcirculatory model of the liver, such as the characteristic transit times through vascular spaces and the ratio of tissue volume to extracellular volume. Using a single injection of a mixture of /sup 3/H-sucrose and /sup 45/Ca/sup 2 +/, the profiles of the efflux of the injected tracers are analyzed to estimate the rate constant for uptake of /sup 45/Ca/sup 2 +/. The estimated rate constant for uptake decreases with increasing perfusate Ca/sup 2 +/ concentration (kin = 0.155 +/- 0.036, 0.0896 +/- 0.024, 0.0713 +/- 0.009 for (Ca/sup 2 +/) = 0.05, 0.5, 1.25 mM; n=5). From these data, estimates for the maximum velocity of uptake of Ca/sup 2 +/ and the Ca/sup 2 +/ concentration for half maximal uptake are calculated to be 0.1208 mM/sec and 0.7278 mM respectively.
- Research Organization:
- Univ. of Texas Health Science Center, San Antonio
- OSTI ID:
- 6274678
- Report Number(s):
- CONF-870644-
- Journal Information:
- Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 46:6; Conference: 78. annual meeting of the American Society of Biological Chemists conference, Philadelphia, PA, USA, 7 Jun 1987
- Country of Publication:
- United States
- Language:
- English
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CALCIUM COMPOUNDS
MEMBRANE TRANSPORT
CALCIUM 45
CARBON 14 COMPOUNDS
CATIONS
LIVER
PERFUSED ORGANS
RATS
SACCHAROSE
TRACER TECHNIQUES
TRITIUM COMPOUNDS
UREA
ALKALINE EARTH ISOTOPES
ALKALINE EARTH METAL COMPOUNDS
AMIDES
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CALCIUM ISOTOPES
CARBOHYDRATES
CARBONIC ACID DERIVATIVES
CHARGED PARTICLES
DAYS LIVING RADIOISOTOPES
DIGESTIVE SYSTEM
DISACCHARIDES
EVEN-ODD NUCLEI
GLANDS
INTERMEDIATE MASS NUCLEI
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ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
MAMMALS
NUCLEI
OLIGOSACCHARIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
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RODENTS
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551001* - Physiological Systems- Tracer Techniques