Mobilization of hepatic calcium pools by platelet activating factor

Journal Article · Tue Mar 24 04:00:00 EST 1987 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00380a012· OSTI ID:6467631

Lapointe, D S; Hanahan, D J; Olson, M S

In the perfused rat liver, platelet activating factor, 1-O-hexadecyl-2-acetyl-sn-glycero-3-phosphocholine (AGEPC), infusion produces an extensive but transient glycogenolytic response which at low AGEPC concentrations is markedly dependent upon the perfusate calcium levels. The role of calcium in the glycogenolytic response of the liver to AGEPC was investigated by assessing the effect of AGEPC on various calcium pools in the intact liver. Livers from fed rats were equilibrated with /sup 45/Ca/sup 2 +/, and the kinetics of /sup 45/Ca/sup 2 +/ efflux were determined in control, AGEPC-stimulated, and phenylephrine-stimulated livers during steady-state washout of /sup 45/Ca/sup 2 +/. AGEPC treatment had only a slight if any effect on the pattern of steady-state calcium efflux from the liver, as opposed to major perturbations in the pattern of calcium efflux effected by the ..cap alpha..-adrenergic agonist phenylephrine. Infusion of short pulses of AGEPC during the washout of /sup 45/Ca/sup 2 +/ from labeled livers caused a transient release of /sup 45/Ca/sup 2 +/ which was not abolished at low calcium concentrations in the perfusate. Infusion of latex beads, which are removed by the reticuloendothelial cells, caused the release of hepatic /sup 45/Ca/sup 2 +/ in a fashion similar to the case with AGEPC. The findings indicate that AGEPC does not perturb a major pool of calcium within the liver as occurs upon ..cap alpha..-adrenergic stimulation; it is likely that AGEPC mobilizes calcium from a smaller yet very important pool, very possibly from nonparenchymal cells in the liver.

• Research Organization: Univ. of Texas Health Science Center, San Antonio
• OSTI ID: 6467631
• Journal Information: Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 26:6; ISSN BICHA
• Country of Publication: United States
• Language: English

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560162* -- Radionuclide Effects
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63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ALCOHOLS
ALKALINE EARTH ISOTOPES
ALKALINE EARTH METAL COMPOUNDS
AMINES
AMMONIUM COMPOUNDS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMISTRY
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BLOOD PLATELETS
BODY
BODY FLUIDS
CALCIUM 45
CALCIUM COMPOUNDS
CALCIUM ISOTOPES
CHEMISTRY
CHOLINE
DAYS LIVING RADIOISOTOPES
DIGESTIVE SYSTEM
DRUGS
ESTERS
EVEN-ODD NUCLEI
GLANDS
HYDROXY COMPOUNDS
INTERMEDIATE MASS NUCLEI
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED POOL TECHNIQUES
LIPIDS
LIPOTROPIC FACTORS
LIVER
MAMMALS
MATERIALS
NUCLEI
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANS
PHOSPHOLIPIDS
QUATERNARY COMPOUNDS
RADIOISOTOPES
RADIONUCLIDE KINETICS
RATS
RODENTS
TRACER TECHNIQUES
VERTEBRATES