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Transient fluxes of intracellular ionized calcium (Ca2+) from intracellular stores are integral components of regulatory signaling pathways operating in numerous biological regulations, including in early stages of egg fertilization. Therefore, we explored whether NADP, which is rapidly generated by phosphorylation of NAD upon fertilization may, directly or(More)
Investigations of recent years revealed that isozymes of cyclic-3', 5'-nucleotide phosphodiesterase (PDE) are a critically important component of the cyclic-3',5'-adenosine monophosphate (cAMP) protein kinase A (PKA) signaling pathway. The superfamily of cyclic-3', 5'-phosphodiesterase (PDE) isozymes consists of at least nine gene families (types): PDE1 to(More)
A polyuric syndrome with nephrogenic diabetes insipidus (NDI) is a frequent consequence of prolonged administration of lithium (Li) salts. Studies in the past, mainly the acute and in vitro experiments, indicated that Li ions can inhibit hydroosmotic effect of [8-arginine]vasopressin (AVP) at the step of cAMP generation in vitro. However, the pathogenesis(More)
We investigated the dependence of nicotinate-adenine dinucleotide phosphate (NAADP)-induced Ca2+ release from intracellular stores of sea urchin egg homogenates, upon extravesicular Ca2+. In contrast to the Ca2+ release induced inositol 1',4',5'-triphosphate (IP3) or cyclic ADP-ribose (cADPR), the Ca2+ release induced by NAADP was completely independent of(More)
We have previously shown that NAD+ inhibits renal Na(+)-Pi symport; however, the biochemical mechanism of NAD+ in this action is not clarified. We now propose that NAD+ acts indirectly by first being converted to cyclic ADP-ribose (cADPR), a potent stimulator of intracellular Ca2+ mobilization. In permeabilized opossum kidney (OK) cells, a cell line often(More)
Nicotinate adenine dinucleotide phosphate (NAADP) was recently identified [Lee and Aarhus (1995) J. Biol. Chem. 270, 2152-2157; Chini, Beers and Dousa (1995) J. Biol. Chem. 270, 3116-3223] as a potent Ca(2+)-releasing agent in sea urchin egg homogenates. NAADP triggered Ca2+ release by a mechanism that was distinct from inositol 1,4,5-trisphosphate (InsP3)-(More)
Signaling via release of Ca2+ from intracellular stores is mediated by several systems, including the inositol 1,4,5-trisphosphate (IP3) and cADP-ribose (cADPR) pathway. We recently discovered a high capacity for cADPR synthesis in rat glomeruli and cultured mesangial cells (MC). We sought to determine whether 1) cADPR synthesis in MC is regulated by(More)
We investigated interactions of phosphonoformic acid (PFA), phosphonoacetic acid (PAA), and other phosphonyl derivatives with the Na+ gradient [Na+ extravesicular greater than Na+ intravesicular; Nao+ greater than Na+i]-dependent transport system for phosphate (Pi) in renal cortical brush border membrane vesicles (BBMV). PFA and PAA inhibited in a(More)
We examined the effect of phosphonoformic acid (PFA) and phosphonoacetic acid (PAA) upon Na+-Pi cotransport in brush-border membrane (BBM) from small gut of rat. Both PFA and PAA inhibited the Na+ gradient-dependent uptake of 32Pi by BBM vesicles (BBMV) prepared from intestinal mucosa but had no effect on Na+-dependent uptakes of D-[3H]glucose,(More)