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Dual excitatory and inhibitory effects of opioids on intracellular calcium in neuroblastoma x glioma hybrid NG108-15 cells.
Mol Pharmacol. 1992 Dec; 42(6):1083-9.MP

Abstract

The intracellular free calcium concentration ([Ca2+]i) was measured in single NG108-15 cells using indo-1-based microfluorimetry. In cells differentiated for 6-14 days in serum-free, forskolin (5 microM)-supplemented medium, application of micromolar concentrations of [D-Ala2,D-Leu5]-enkephalin (DADLE) inhibited Ca2+ influx mediated by voltage-gated Ca2+ channels. DADLE, at concentrations ranging from 1 nM to 1 microM, also produced rapid transient increases in [Ca2+]i (EC50 = 10 nM). The [Ca2+]i increases elicited by DADLE did not correlate with the inhibitory effects of the peptide. DADLE-induced [Ca2+]i increases were blocked by naloxone. In single cells, sequential application of selective opioid agonists (30 nM) evoked responses of the rank order DADLE = [D-Pen2,D-Pen5]-enkephalin > (trans)-(+-)-3,4-dichloro-N-methyl-N-(2-[1-pyrrolidinyl]cyclohexyl) benzeneacetamide > [D-Ala2,N-Me-Phe4,Gly5-ol]-enkephalin, consistent with activation of a delta-opioid receptor. The response was completely blocked by removal of extracellular Ca2+ or application of 1 microM nitrendipine, indicating that the increase in [Ca2+]i results from Ca2+ influx via dihydropyridine-sensitive, voltage-gated Ca2+ channels. Substitution of N-methyl-D-glucamine for extracellular Na+ or application of 1 microM tetrodotoxin greatly reduced, and in some cases blocked, the DADLE-induced [Ca2+]i increase, consistent with amplification of the response by voltage-gated Na+ channels. The [Ca2+]i increase was mimicked by both dibutyryl-cAMP and phorbol 12,13-dibutyrate. These findings are consistent with a delta-opioid-induced depolarization, possibly mediated by a second messenger, that subsequently recruits voltage-sensitive Ca2+ channels. In contrast to differentiated cells, undifferentiated cells responded to DADLE with a modest [Ca2+]i increase that was not sensitive to nitrendipine. In these cells, activation of the same second messenger system may elevate [Ca2+]i by mobilization from intracellular stores rather than influx. In addition to previously described inhibitory coupling to adenylyl cyclase and Ca2+ channels in NG108-15 cells, these results suggest that a novel, excitatory, effector system may also couple to opioid receptors.

Authors+Show Affiliations

Department of Pharmacology, University of Minnesota Medical School, Minneapolis 55455.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

1336113

Citation

Jin, W, et al. "Dual Excitatory and Inhibitory Effects of Opioids On Intracellular Calcium in Neuroblastoma X Glioma Hybrid NG108-15 Cells." Molecular Pharmacology, vol. 42, no. 6, 1992, pp. 1083-9.
Jin W, Lee NM, Loh HH, et al. Dual excitatory and inhibitory effects of opioids on intracellular calcium in neuroblastoma x glioma hybrid NG108-15 cells. Mol Pharmacol. 1992;42(6):1083-9.
Jin, W., Lee, N. M., Loh, H. H., & Thayer, S. A. (1992). Dual excitatory and inhibitory effects of opioids on intracellular calcium in neuroblastoma x glioma hybrid NG108-15 cells. Molecular Pharmacology, 42(6), 1083-9.
Jin W, et al. Dual Excitatory and Inhibitory Effects of Opioids On Intracellular Calcium in Neuroblastoma X Glioma Hybrid NG108-15 Cells. Mol Pharmacol. 1992;42(6):1083-9. PubMed PMID: 1336113.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Dual excitatory and inhibitory effects of opioids on intracellular calcium in neuroblastoma x glioma hybrid NG108-15 cells. AU - Jin,W, AU - Lee,N M, AU - Loh,H H, AU - Thayer,S A, PY - 1992/12/1/pubmed PY - 1992/12/1/medline PY - 1992/12/1/entrez SP - 1083 EP - 9 JF - Molecular pharmacology JO - Mol Pharmacol VL - 42 IS - 6 N2 - The intracellular free calcium concentration ([Ca2+]i) was measured in single NG108-15 cells using indo-1-based microfluorimetry. In cells differentiated for 6-14 days in serum-free, forskolin (5 microM)-supplemented medium, application of micromolar concentrations of [D-Ala2,D-Leu5]-enkephalin (DADLE) inhibited Ca2+ influx mediated by voltage-gated Ca2+ channels. DADLE, at concentrations ranging from 1 nM to 1 microM, also produced rapid transient increases in [Ca2+]i (EC50 = 10 nM). The [Ca2+]i increases elicited by DADLE did not correlate with the inhibitory effects of the peptide. DADLE-induced [Ca2+]i increases were blocked by naloxone. In single cells, sequential application of selective opioid agonists (30 nM) evoked responses of the rank order DADLE = [D-Pen2,D-Pen5]-enkephalin > (trans)-(+-)-3,4-dichloro-N-methyl-N-(2-[1-pyrrolidinyl]cyclohexyl) benzeneacetamide > [D-Ala2,N-Me-Phe4,Gly5-ol]-enkephalin, consistent with activation of a delta-opioid receptor. The response was completely blocked by removal of extracellular Ca2+ or application of 1 microM nitrendipine, indicating that the increase in [Ca2+]i results from Ca2+ influx via dihydropyridine-sensitive, voltage-gated Ca2+ channels. Substitution of N-methyl-D-glucamine for extracellular Na+ or application of 1 microM tetrodotoxin greatly reduced, and in some cases blocked, the DADLE-induced [Ca2+]i increase, consistent with amplification of the response by voltage-gated Na+ channels. The [Ca2+]i increase was mimicked by both dibutyryl-cAMP and phorbol 12,13-dibutyrate. These findings are consistent with a delta-opioid-induced depolarization, possibly mediated by a second messenger, that subsequently recruits voltage-sensitive Ca2+ channels. In contrast to differentiated cells, undifferentiated cells responded to DADLE with a modest [Ca2+]i increase that was not sensitive to nitrendipine. In these cells, activation of the same second messenger system may elevate [Ca2+]i by mobilization from intracellular stores rather than influx. In addition to previously described inhibitory coupling to adenylyl cyclase and Ca2+ channels in NG108-15 cells, these results suggest that a novel, excitatory, effector system may also couple to opioid receptors. SN - 0026-895X UR - https://www.unboundmedicine.com/medline/citation/1336113/Dual_excitatory_and_inhibitory_effects_of_opioids_on_intracellular_calcium_in_neuroblastoma_x_glioma_hybrid_NG108_15_cells_ L2 - http://molpharm.aspetjournals.org/cgi/pmidlookup?view=long&pmid=1336113 DB - PRIME DP - Unbound Medicine ER -