Neurotensin stimulates inositol phospholipid metabolism and calcium mobilization in murine neuroblastoma clone N1E-115.
Murine neuroblastoma cells (clone N1E-115) possess neurotensin receptors that mediate cyclic GMP synthesis. Because of the hypothesized relationship between phospholipid metabolism, intracellular Ca2+, and cyclic GMP synthesis, we determined with these cells the effects of neurotensin on 32P labeling of phospholipids, release of inositol phosphates, and intracellular Ca2+ (as determined with the use of Quin-2, a fluorescent probe sensitive to free Ca2+ levels). Neurotensin stimulated incorporation of 32P into phospholipids, especially phosphatidylinositol and phosphatidate. Neurotensin also stimulated the release of [3H]inositol phosphates with an EC50 of about 1 nM. Mean basal Ca2+ concentration in these cells was 134 nM and this level was increased in a rapid and dose-dependent manner by neurotensin, with an EC50 of 4 nM. Since the EC50 for neurotensin in stimulating cyclic GMP synthesis is 1.5 nM and the KD for binding of [3H]neurotensin at 0 degrees C is 11 nM, all these different effects appear to be shared proximal consequences of neurotensin receptor activation.
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D002999:Clone Cells / Q000378:metabolism; D006152:Cyclic GMP / Q000096:biosynthesis; D007294:Inositol / Q000378:metabolism; D007295:Inositol Phosphates / Q000378:metabolism; D051379:Mice; D009447:Neuroblastoma / Q000378:metabolism*; D009496:Neurotensin / Q000494:pharmacology*; D010712:Phosphatidic Acids / Q000378:metabolism; D010716:Phosphatidylinositols / Q000378:metabolism*; D018028:Receptors, Neurotensin; D017981:Receptors, Neurotransmitter / Q000502:physiology
D007295:Inositol Phosphates; D010712:Phosphatidic Acids; D010716:Phosphatidylinositols; D018028:Receptors, Neurotensin; D017981:Receptors, Neurotransmitter; D009496:Neurotensin; D007294:Inositol; D006152:Cyclic GMP; D002118:Calcium