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Biscoclaurine alkaloids inhibit receptor-mediated phospholipase A2 activation probably through uncoupling of a GTP-binding protein from the enzyme in rat peritoneal mast cells.
Biochem Pharmacol. 1992 Jul 07; 44(1):45-50.BP

Abstract

The mechanism underlying the inhibitory effect of biscoclaurine (bisbenzylisoquinoline) alkaloids on phospholipase A2 activation in the signalling system of stimulated rat peritoneal mast cells was studied. Cepharanthine, berbamine and isotetrandrine inhibited antigen- and compound 48/80-induced arachidonic acid liberation, but not diacylglycerol formation or histamine release. They had no effect on A23187-induced arachidonic acid liberation, which was prevented by p-bromophenacyl bromide, a known phospholipase A2 inhibitor, and also did not affect phospholipase A2 activity in a cell-free system including an exogenous phospholipid substrate. Each alkaloid also inhibited arachidonic acid liberation induced by guanosine 5'-O-(3-thiotriphosphate) in saponin-permeabilized mast cells, and by mastoparan or NaF plus AlCl3 intact cells. Furthermore, each alkaloid abolished the inhibitory effect of islet-activating protein on the compound 48/80-induced arachidonic acid liberation. These data suggest that these alkaloids suppress the receptor-mediated phospholipase A2 activation through, at least in part, uncoupling of a GTP-binding protein from the enzyme, rather than by affecting the enzyme directly.

Authors+Show Affiliations

Department of Biochemistry, Kyoto Pharmaceutical University, Japan.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

1632837

Citation

Akiba, S, et al. "Biscoclaurine Alkaloids Inhibit Receptor-mediated Phospholipase A2 Activation Probably Through Uncoupling of a GTP-binding Protein From the Enzyme in Rat Peritoneal Mast Cells." Biochemical Pharmacology, vol. 44, no. 1, 1992, pp. 45-50.
Akiba S, Kato E, Sato T, et al. Biscoclaurine alkaloids inhibit receptor-mediated phospholipase A2 activation probably through uncoupling of a GTP-binding protein from the enzyme in rat peritoneal mast cells. Biochem Pharmacol. 1992;44(1):45-50.
Akiba, S., Kato, E., Sato, T., & Fujii, T. (1992). Biscoclaurine alkaloids inhibit receptor-mediated phospholipase A2 activation probably through uncoupling of a GTP-binding protein from the enzyme in rat peritoneal mast cells. Biochemical Pharmacology, 44(1), 45-50.
Akiba S, et al. Biscoclaurine Alkaloids Inhibit Receptor-mediated Phospholipase A2 Activation Probably Through Uncoupling of a GTP-binding Protein From the Enzyme in Rat Peritoneal Mast Cells. Biochem Pharmacol. 1992 Jul 7;44(1):45-50. PubMed PMID: 1632837.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Biscoclaurine alkaloids inhibit receptor-mediated phospholipase A2 activation probably through uncoupling of a GTP-binding protein from the enzyme in rat peritoneal mast cells. AU - Akiba,S, AU - Kato,E, AU - Sato,T, AU - Fujii,T, PY - 1992/7/7/pubmed PY - 1992/7/7/medline PY - 1992/7/7/entrez SP - 45 EP - 50 JF - Biochemical pharmacology JO - Biochem Pharmacol VL - 44 IS - 1 N2 - The mechanism underlying the inhibitory effect of biscoclaurine (bisbenzylisoquinoline) alkaloids on phospholipase A2 activation in the signalling system of stimulated rat peritoneal mast cells was studied. Cepharanthine, berbamine and isotetrandrine inhibited antigen- and compound 48/80-induced arachidonic acid liberation, but not diacylglycerol formation or histamine release. They had no effect on A23187-induced arachidonic acid liberation, which was prevented by p-bromophenacyl bromide, a known phospholipase A2 inhibitor, and also did not affect phospholipase A2 activity in a cell-free system including an exogenous phospholipid substrate. Each alkaloid also inhibited arachidonic acid liberation induced by guanosine 5'-O-(3-thiotriphosphate) in saponin-permeabilized mast cells, and by mastoparan or NaF plus AlCl3 intact cells. Furthermore, each alkaloid abolished the inhibitory effect of islet-activating protein on the compound 48/80-induced arachidonic acid liberation. These data suggest that these alkaloids suppress the receptor-mediated phospholipase A2 activation through, at least in part, uncoupling of a GTP-binding protein from the enzyme, rather than by affecting the enzyme directly. SN - 0006-2952 UR - https://www.unboundmedicine.com/medline/citation/1632837/Biscoclaurine_alkaloids_inhibit_receptor_mediated_phospholipase_A2_activation_probably_through_uncoupling_of_a_GTP_binding_protein_from_the_enzyme_in_rat_peritoneal_mast_cells_ DB - PRIME DP - Unbound Medicine ER -