A high n-6 polyunsaturated fatty acid diet reduces muscarinic M2/M4 receptor binding in the rat brain.
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.
du Bois
Teresa Marie
TM
Neuroscience Institute of Schizophrenia and Allied Disorders (NISAD), Molecular Neurobiology Laboratory, Department of Biomedical Science, University of Wollongong, NSW, Australia.
Bell
Warren
W
Deng
Chao
C
Huang
Xu-Feng
XF
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
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