Miguel Trueba

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Ceramide 1-phosphate (C1P) is a bioactive sphingolipid that is implicated in the regulation of cell homeostasis and the control of inflammation. It is mitogenic for fibroblasts and macrophages, and has been described as potent inhibitor of apoptosis. Using RAW 264.7 macrophages we have now discovered a new biological activity of C1P: stimulation of cell(More)
1. The presence of sites specifically binding [3H]cortisol in plasma membrane isolated from chicken liver has been determined. The kinetic parameters of this binding are: Kd = 4.5 nM and Bmax = 2225 fmol/mg protein in presence of 10(-6) M progesterone. 2. The affinities of several natural and synthetic steroids for the membrane binding site respect to the(More)
Sphingolipids are essential components of cell membranes, and many of them regulate vital cell functions. In particular, ceramide plays crucial roles in cell signaling processes. Two major actions of ceramides are the promotion of cell cycle arrest and the induction of apoptosis. Phosphorylation of ceramide produces ceramide 1-phosphate (C1P), which has(More)
1. The pharmacological properties of F-180, a vasopressin (VP) structural analogue, were determined on CHO cells expressing the different human vasopressin and oxytocin (OT) receptor subtypes. Binding experiments revealed that F-180 exhibited a high affinity for the human V(1a) receptor subtype (K(i)=11 nM) and was selective for this receptor subtype. 2.(More)
Sphingolipids are major constituents of biological membranes of eukaryotic cells. Many studies have shown that sphingomyelin (SM) is a major phospholipid in cell bilayers and is mainly localized to the plasma membrane of cells, where it serves both as a building block for cell architecture and as a precursor of bioactive sphingolipids. In particular,(More)
We have investigated the effect of NiCl2 on platelet activation induced by thrombin, phorbol 12-myristate 13-acetate, and calcium ionophores. Besides blocking Ca2+ influx, NiCl2 inhibited platelet aggregation, intracellular Ca2+ mobilization, and phospholipase C activation induced by thrombin in a dose-dependent manner. In contrast to ionomycin, NiCl2(More)
Specific corticosterone binding to calf adrenal cortex plasma membrane was measured using the biologically active radioligand [3H]corticosterone. Corticosterone binding was found to be time-dependent, saturable and reversible, and was reduced by more than 70% when membranes were pretreated with proteases. The population of corticosterone binding sites in(More)
Specific binding for progesterone has been determined in rat hepatocytes and mouse liver purified plasma membranes. The binding is saturable, reversible and temperature dependent. Two types of binding sites have been characterized in hepatocytes. The first is of high affinity and low binding capacity and the other one is of low affinity and high capacity of(More)
A cortisol binding protein from rat liver plasma membranes has been solubilized in active form by using the zwitterionic detergent CHAPS. Two types of binding sites have been characterised in both native and solubilized membranes. The first is of high affinity and low binding capacity (12 nM; 946 fmol/mg) and the other one is of low affinity and high(More)
Different drugs that elevate the cGMP levels inhibit the agonist-induced platelet activation. The mechanisms of action of cGMP probably include inhibition of both phospholipase C and the increase in intracellular Ca2+ concentration, and these effects seem to be mediated by cGMP-dependent protein kinases. However, in most studies, cells were preincubated(More)