scholarly journals μ-opioids activate phospholipase C in SH-SY5Y human neuroblastoma cells via calcium-channel opening

1995 ◽  
Vol 305 (2) ◽  
pp. 577-581 ◽  
Author(s):  
D Smart ◽  
G Smith ◽  
D G Lambert
Keyword(s):  
Phospholipase C ◽  
Opioid Receptor ◽  
Neuroblastoma Cells ◽  
Receptor Occupancy ◽  
Mu Opioid Receptor ◽  
Human Neuroblastoma ◽  
Mu Opioid ◽  
Inositol 1,4,5 Trisphosphate ◽  
Dependent Inhibition ◽  
Dose Dependent

We have recently reported that, in SH-SY5Y cells, mu-opioid receptor occupancy activates phospholipase C via a pertussis toxin-sensitive G-protein. In the present study we have further characterized the mechanisms involved in this process. Fentanyl (0.1 microM) caused a monophasic increase in inositol 1,4,5-trisphosphate mass formation, with a peak (20.5 +/- 3.6 pmol/mg of protein) at 15 s. Incubation in Ca(2+)-free buffer abolished this response, while Ca2+ replacement 1 min later restored the stimulation of inositol 1,4,5-trisphosphate formation (20.1 +/- 0.6 pmol/mg of protein). In addition, nifedipine (1 nM-0.1 mM), an L-type Ca(2+)-channel antagonist, caused a dose-dependent inhibition of inositol 1,4,5-trisphosphate formation, with an IC50 of 60.3 +/- 1.1 nM. Elevation of endogenous beta/gamma subunits by selective activation of delta-opioid and alpha 2 adrenoceptors failed to stimulate phospholipase C. Fentanyl also caused a dose-dependent (EC50 of 16.2 +/- 1.0 nM), additive enhancement of carbachol-induced inositol 1,4,5-trisphosphate formation. In summary, we have demonstrated that in SH-SY5Y cells activation of the mu-opioid receptor allows Ca2+ influx to activate phospholipase C. However, the possible role of this mechanism in the process of analgesia remains to be elucidated.

scholarly journals Diffusion of the mu opioid receptor at the surface of human neuroblastoma SH-SY5Y cells is restricted to permeable domains

FEBS Letters ◽  
2006 ◽  
Vol 580 (22) ◽  
pp. 5227-5231 ◽  
Author(s):  
Aude Saulière ◽  
Gérald Gaibelet ◽  
Claire Millot ◽  
Serge Mazères ◽  
André Lopez ◽  
...  
Keyword(s):  
Opioid Receptor ◽  
Mu Opioid Receptor ◽  
Human Neuroblastoma ◽  
Mu Opioid

scholarly journals Time-dependent effects of lithium on the agonist-stimulated accumulation of second messenger inositol 1,4,5-trisphosphate in SH-SY5Y human neuroblastoma cells

1995 ◽  
Vol 311 (1) ◽  
pp. 225-232 ◽  
Author(s):  
G V Los ◽  
I P Artemenko ◽  
L E Hokin
Keyword(s):  
Phospholipase C ◽  
Direct Effect ◽  
Neuroblastoma Cells ◽  
Bipolar Disorders ◽  
Rapid Decline ◽  
Resting Cells ◽  
Human Neuroblastoma ◽  
Metabolizing Enzymes ◽  
Inositol 1,4,5 Trisphosphate ◽  
Stimulation Of

In order to approach the molecular mechanism of Li+'s mood-stabilizing action, the effect of Li+ (LiCl) on inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] mass was investigated in human neuroblastoma SH-SY5Y cells, which express muscarinic M3 receptors, coupled to PtdIns hydrolysis. Stimulation of these cells, with the cholinergic agonist acetylcholine, resulted in a rapid and transient increase in Ins(1,4,5)P3 with a maximum at 10 s. This was followed by a rapid decline in Ins(1,4,5)P3 within 30 s to a plateau level above baseline, which gradually declined to reach a new steady state, which was significantly higher than resting Ins(1,4,5)P3 at 30 min. Li+ had no effect on Ins(1,4,5)P3 in resting cells, as well as on the acetylcholine-dependent peak of Ins(1,4,5)P3. However, Li+ caused a transient reduction (at 45 s), followed by a long lasting increase in the Ins(1,4,5)P3 (30 min), as compared with controls. The Li+ effects were dose-dependent and were observed at concentrations used in the treatment of bipolar disorders. Supplementation with inositol had no effect on the level of Ins(1,4,5)P3, at least over the time periods studied. Stimulation of muscarinic receptors with consequent activation of phospholipase C were necessary for the manifestation of Li+ effects in SH-SY5Y cells, Li+ did not interfere with degradation of Ins(1,4,5)P3 after receptor-blockade with atropine, suggesting that Li+ has no direct effect on the Ins(1,4,5)P3-metabolizing enzymes. A direct effect of Li+ on the phospholipase C also is unlikely. Blockade of Ca2+ entry into the cells by Ni2+, or incubation with EGTA, which reduces agonist-stimulated accumulation of Ins(1,4,5)P3, had no effect on the Li(+)-dependent increase in Ins(1,4,5)P3.

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