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Histamine Acting on H 2 Receptors Stimulates Phospholipid Methylation in Synaptic Membranes of Rat Brain
Author(s) -
Ozawa Koichiro,
Nomura Yasuyuki,
Segawa Tomio
Publication year - 1987
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1987.tb05676.x
Subject(s) - synaptic membrane , phospholipid , chemistry , histamine , membrane , neuroscience , receptor , methylation , neurotransmission , biophysics , microbiology and biotechnology , biochemistry , biology , pharmacology , gene
Histamine stimulated [ 3 H]methyl group incorporation into phospholipids in crude synaptic membranes of rat whole brain (without cerebellum) in modified Krebs‐Ringer solution containing the methyl donor S ‐adenosyl‐[ wethyl ‐ 3 H]methionine. The transient increase of [ 3 H]‐methyl incorporation into lipids peaked within 45 s after addition of histamine (5 or 10 μ M ) and decreased the basal level in 60 s. Histamine‐stimulated [ 3 HJmethyl incorporation was increased linearly in a protein concentration‐dependent manner. The stimulation was temperature and histamine concentration dependent. TLC analysis of a chloroform/methanol extract indicated that radioactive phospholipids (phosphatidylcholine, phosphatidyl‐ N,N ‐dimethylethanolamine, and phosphatidyl‐ N ‐monomethylethanolamine) accounted for 60–65% of the total radioactivity recovered. The synaptosomal fraction had the highest specific activity of all the subfractions of crude synaptic membranes (P 2 ). Histamine‐induced [ 3 H]methyl incorporation was inhibited by addition of cimetidine (0.01–10 μ M ) or famotidine (0.01–1.0 μ M ) in a concentration‐dependent manner but not by mepyramine (0.1–10 μ M ) or diphenhydramine (0.1–10 μ M ). The stimulation of [ 3 H]methyl incorporation was also observed by addition of impromidine (0.01–10 μ M ) or dimaprit (1.0 μ M‐ 1.0 m M ) in a concentration‐dependent manner but not by 2‐pyridylethylamine (1.0 μ M‐ 1.0 m M ). These results indicate that phospholipid methylation is induced by histamine acting on H 2 receptors in rat brain synaptosomes.