J A Creba

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It now appears to be generally agreed that the 'phosphatidylinositol response', discovered in 1953 by Hokin & Hokin, occurs universally when cells are stimulated by ligands that cause an elevation of the ionized calcium concentration of the cytosol. The initiating reaction is almost certainly hydrolysis of an inositol lipid by a phosphodiesterase.(More)
Rat hepatocytes rapidly incorporate [32P]Pi into phosphatidylinositol 4-phosphate (PtdIns4P) and phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2]; their monoester phosphate groups approach isotopic equilibrium with the cellular precursor pools within 1 h. Upon stimulation of these prelabelled cells with Ca2+-mobilizing stimuli (V1-vasopressin,(More)
Serotonin (5-HT) induces inositol phosphate production and the efflux of 45Ca2+ in a smooth muscle cell line (A7r5) derived from rat aorta. These effects were pharmacologically characterised and compared to data obtained in radioligand binding studies performed with the 5-HT2 ligand [3H]ketanserin in rat brain cortex membranes. 5-HT causes in increase in(More)
HL60 cells were adapted to grow in a serum-free medium containing 1 mg l-1 inositol, in which they differentiated normally towards neutrophils (in 0.9% by volume dimethylsulphoxide) and towards monocytes (in 10 nM phorbol myristate acetate). Cells that had been equilibrium-labelled with [2-3H]myo-inositol contained a complex pattern of inositol metabolites,(More)
DMSO differentiated U937 cells responded to 10(-6) M LTD4, LTB4 and FMLP with an increase in both InsP formation and [Ca2+]i. FMLP caused a greater rise in InsPs than either LTD4 or LTB4, which were equivalent. LTD4, however, caused a greater increase in [Ca2+]i than LTB4 (4-fold) or FMLP. The FMLP [Ca2+]i and InsP responses were abolished by pertussis(More)
Addition of nafenopin (30-300 microM to 45Ca2+ preloaded cultured hepatocytes caused a rapid and concentration-dependent increase in 45Ca2+ efflux in a manner similar to vasopressin, as evidenced by the loss of radioactivity from the cells. In contrast to vasopressin, addition of nafenopin to [3H]inositol prelabelled hepatocytes in culture did not increase(More)
All hormones and neurotransmitters which provoke their intracellular effects by increasing the cytosolic concentration of Ca2+ in their target cells also stimulate the breakdown of inositol phospholipids. Much evidence suggests that this breakdown is intimately involved in the mechanism which couples cell-surface receptor activation to intracellular Ca2+(More)