The effects of serum on inositol 1,4,5-trisphosphate (IP3) formation and Ca2+ mobilization in the human submandibular cell line A253 were studied. Exposure of A253 cells to fetal bovine serum (FBS) elicited a 3.3-fold increase in IP3 formation and a concentration-dependent transient increase in cytosolic free Ca2+ concentration ([Ca2+]i), which was similar in Ca2+-containing and Ca2+-free media.
View Article and Find Full Text PDFComp Biochem Physiol C Pharmacol Toxicol Endocrinol
August 1998
The present study investigated the effects of the catecholamine-depleting drug reserpine on cellular Ca2+ storage and mobilization in rat submandibular acinar cells. Adult rats received seven daily injections of reserpine (0.5 mg/kg) and inositol 1,4,5-trisphosphate (IP3) formation and Ca2+ mobilization were measured in isolated submandibular acinar cells.
View Article and Find Full Text PDFParticulate and soluble (1-3)-beta-glucans are effective in preventing infections by enhancing macrophage and neutrophil functions. However, the mechanisms triggering these enhanced cellular responses are essentially unknown. We recently demonstrated that zymosan, a particulate (1-3)-beta-glucan receptor agonist, caused an influx of Ca2+ in NR8383 rat alveolar macrophages (AMs) and a resulting increase in intracellular Ca2+ (Zhang et al.
View Article and Find Full Text PDFJ Leukoc Biol
September 1997
Ca2+ mobilization in the rat alveolar macrophage cell line NR8383 was examined with the Ca2+-sensitive fluorescent probe Fura-2. ATP and norepinephrine elicited a 108 and 46% increase, respectively, in cytosolic free Ca2+ concentration ([Ca2+]i). Acetylcholine, nicotine, isoproterenol, substance P, and vasoactive intestinal polypeptide did not alter [Ca2+]i.
View Article and Find Full Text PDFProc Soc Exp Biol Med
October 1997
The regulation of Ca2+ mobilization in the human submandibular duct cell line A253 was investigated by monitoring cytosolic free Ca2+ concentrations ([Ca2+]i) using the Ca(2+)-sensitive fluorescent indicator fura-2 and by measuring inositol 1,4,5-triphosphate (IP3) formation. An increase in [Ca2+]i was elicited by ATP, isoproterenol (IPR), or vasoactive intestinal polypeptide (VIP), but not by acetylcholine, norepinephrine, or substance P, suggesting that Ca2+ mobilization is regulated by P2-purinergic, beta 2-adrenergic, and VIP receptors. 1,4,5-IP3 formation was significantly increased by ATP but not by the other agonists.
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