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G Cremel

Publications and source records attributed to G Cremel.

25 records · Page 2Linked to original sources
PubMed1980

Does PGE1 induce modifications at the membrane level of bone marrow macrophages? A fluorescence study.

The effect of prostaglandin E1 (PGE1), and F2 alpha (PGF2 alpha) on the surface membrane configuration of bone marrow macrophages was studied. We measured the fluorescence intensity of membrane bound ANS in prostaglandin pretreated cells. The effect on fluorescence intensity of a blocker of the prostaglandin binding site (SC19220) and inhibitors of prostaglandin synthesis (aspirin, indomethacin, diclophenate, Eicosa 5,8,11,14 tetraynoic acid) also were studied. Enhancement of the fluorescence intensity of bound ANS in cells pretreated with PGE1 indicates a conformational change localized at the membrane surface. That those changes are confined to the cell surface was shown by the failure of PGE1 or PGF2 alpha to alter the fluorescence polarization of bound DPH used as indicator of membrane core viscosity. Our data indicate that PGE1 could act at the surface of the membrane and that its action causes rapid structural perturbation at strategic points in the molecular organization of the membrane of bone marrow macrophages.

Anilino Naphthalenesulfonates↗
PubMed1980

Influence of acetylcholine on rebinding of soluble acetylcholinesterase to a synaptosomal fraction from rat brain.

Acetylcholinesterase (Acetylcholine acetylhydrolase E.C. 3.1.1.7.) released from a rat brain synaptosomal fraction was shown to rebind upon incubation in the presence of 3 mM acetylcholine. This action was shown to be reversible. Glutamate, aspartate and gamma-aminobutyrate antagonise this effect. Solubilization of both bulk protein and acetylcholinesterase by Lubrol WX and triton X 100 after acetylcholine incubation of synaptosomal fractions is much lower than in the non incubated preparation. Local production of protons due to the hydrolysis of acetylcholine by the enzyme could partially explain the reassociation of the enzyme. We suggest that the observed phenomenon may play some physiological role in the function of acetylcholinesterase.

Acetylcholine↗
PubMed1977

Intramitochondrial intermembranal reversible translocation of aspartate aminotransferase and malate dehydrogenase through the inner mitochondrial membrane.

The translocation of aspartate aminotransferase, malate dehydrogenase, and bulk protein from the rat liver inner mitochondrial membrane and matrix toward the intermembranal space induced by certain organic acids (movement effectors) has been studied. Experiments involving a two-stage dissolution of the mitochondrial membranes by the use of detergents strongly suggest that enzymes like aspartate amino-transferase can cross the inner mitochondrial membrane providing exogenous movement effector was present. Experiments which measured the changes in membranal distribution of malate dehydrogenase induced by the movement effectors also suggested the occurrence of a similar phenomenon for this enzyme in intact mitochondria. Control experiments revealed that under our experimental conditions, the inner mitochondrial membrane remained impermeable to small molecules, e.g., sucrose, and that the release of aspartate aminotransferease, malate dehydrogenase, insocitrate dehydrogenase, and bulk protein into the intermembranal space in the presence of succinate occurred at a much lower concentration of digitonin than that required to disrupt the inner mitochondrial membrane.

Animals↗