title: A high n-6 polyunsaturated fatty acid diet reduces muscarinic M2/M4 receptor binding in the rat brain.
abstract: The aim of this study was to examine the influence of different fat diets on muscarinic acetylcholine receptor binding. Nineteen male Sprague-Dawley rats were divided into four groups and fed a diet of either high saturated fat, n-6 polyunsaturated fatty acid (PUFA), n-3 PUFA or low fat (control) for 8 weeks. Using quantitative autoradiography, [(3)H]pirenzepine binding to muscarinic M1/M4 receptors and [(3)H]AF-DX384 binding to M2/M4 receptors were measured throughout the brain in all four groups. The main findings were that compared to the low fat control group, M2/M4 receptor binding was significantly reduced in the dorsolateral, dorsomedial and ventromedial parts of the caudate putamen (61-64%, p < 0.05), anterior cingulate cortex (59%, p < 0.01), dentate gyrus and CA1-3 fields of the hippocampus (32-43%, p < 0.01) of rats on a high n-6 PUFA diet; however, no differences in M1/M4 receptor binding densities between the four groups were observed. These results suggest that a diet high in n-6 PUFA, but not of n-3 PUFAs or saturated fat, may selectively alter M2/M4 receptor-mediated signal transduction in the rat brain.
authors.affiliation: Neuroscience Institute of Schizophrenia and Allied Disorders (NISAD), Molecular Neurobiology Laboratory, Department of Biomedical Science, University of Wollongong, NSW, Australia.
authors.forename: Teresa Marie
authors.initials: TM
authors.lastname: du Bois
authors.forename: Warren
authors.initials: W
authors.lastname: Bell
authors.forename: Chao
authors.initials: C
authors.lastname: Deng
authors.forename: Xu-Feng
authors.initials: XF
authors.lastname: Huang
mesh_terms: D000109:Acetylcholine / Q000378:metabolism; D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism; D001667:Binding, Competitive / Q000187:drug effects / Q000502:physiology*; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D001931:Brain Mapping; D015536:Down-Regulation / Q000187:drug effects / Q000502:physiology; D015525:Fatty Acids, Omega-3 / Q000378:metabolism / Q000494:pharmacology; D043371:Fatty Acids, Omega-6 / Q000378:metabolism / Q000494:pharmacology*; D005526:Food, Formulated; D005527:Food, Fortified; D008297:Male; D018727:Muscarinic Antagonists / Q000378:metabolism; D010276:Parasympatholytics / Q000378:metabolism; D010890:Pirenzepine / Q000378:metabolism; D011869:Radioligand Assay; D051381:Rats; D017207:Rats, Sprague-Dawley; D043585:Receptor, Muscarinic M2 / Q000187:drug effects / Q000378:metabolism*; D043588:Receptor, Muscarinic M4 / Q000187:drug effects / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D009435:Synaptic Transmission / Q000502:physiology
chemical_list: D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D018727:Muscarinic Antagonists; D010276:Parasympatholytics; D043585:Receptor, Muscarinic M2; D043588:Receptor, Muscarinic M4; D016718:Arachidonic Acid; D010890:Pirenzepine; D000109:Acetylcholine