7 results match your criteria: "Sanofi-Pharma Research Centre[Affiliation]"

The binding of fantofarone, a novel calcium channel antagonist, to cytoplasmic membranes and lipid vesicles has been studied by means of its fluorescence. The binding characteristics (dissociation constant Kd and total number of binding sites Bmax) were determined using saturation isotherms. In brain synaptic and cardiac sarcolemmal membranes, fantofarone binds to a single site with a Kd value of approximately 1.

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Using the fluorescent properties of fantofarone, we have studied the interactions between this novel calcium entry blocker and human and bovine serum albumins. Binding of fantofarone, which is poorly fluorescent in aqueous buffer, resulted in a large increase in the fluorescent signal (lambda ex = 335 nm, lambda em = 395 nm). Fantofarone bound to a single site with a dissociation constant (Kd) of 11-12 x 10(-6) M.

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SR 33805 is a representative of a new class of compounds (indole sulfone) that inhibits L-type Ca2+ channels. [3H]SR 33805 has been shown to bind with a high affinity (Kd approximately 20 pM calculated from saturation isotherms and association/dissociation kinetics) to a single site in a purified preparation of rat cardiac sarcolemmal membranes. The binding was found to be saturable and reversible.

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[3H]SR 47436, a selective and potent novel non-peptide antagonist of angiotensin receptors, was used to characterize the cardiac angiotensin AT1 receptors. In neonatal rat heart cells, Scatchard analysis showed a single class of high affinity binding sites (Kd = 0.24 nM, Bmax = 28 fmol/mg protein).

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In this study, SR 33805 was shown to inhibit competitively [3H]fantofarone binding to cardiac sarcolemmal membranes. In contrast, SR 33805 was shown to inhibit allosterically [3H](+)-PN200-110, [3H](-)-D888 and cis-(+)-[3H]diltiazem binding. In isolated rabbit atrial preparations, SR 33805 was shown to be the least potent of fantofarone, nifedipine, verapamil and diltiazem in terms of both negative chronotropic and inotropic responses (IC50's 6 and 12 microM, respectively).

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The effect of SR 33557, a novel calcium entry blocker, on calcium overload, and regulation of calcium channels and beta-adrenergic receptors was investigated in the rat heart. Calcium overload and infarct-like lesions were produced by a large dose of isoproterenol (40 mg/kg, subcutaneously) to rats. Calcium overload was maximal 8 hours after administration of isoproterenol (control: 5.

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The fluorescent properties of SR 33557, a novel calcium entry blocker, have been characterized in solution and when interacting with phospholipid vesicles and natural membranes. The intensity and lifetime of fluorescence emission increased directly as a function of the decrease in the solvent dielectric constant (epsilon) with no change in the emission wavelength maxima. The quantum yield and the fluorescence lifetime in dioxane were 0.

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