GTP effects in rat brain slices support the non-interconvertability of M1 and M2 muscarinic acetylcholine receptors.
GTP (guanosine-5'-triphosphate) markedly reduced high-affinity 3H-oxotremorine-M binding to M2 receptors on brain slices in autoradiographic experiments while 3H-pirenzepine binding to M1 receptors was largely unaffected. The distribution of M1 receptors so labelled was also not altered by GTP to include former M2-rich regions, thus indicating that GTP could not, by itself, interconvert high agonist-affinity M2 receptors to M1 receptors.
Spencer
D G
DG
Neurobiology Department, Troponwerke, Cologne, Federal Republic of Germany.
Horváth
E
E
Traber
J
J
Van Rooijen
L A
LA
D000818:Animals; D001345:Autoradiography; D001921:Brain / Q000378:metabolism*; D006160:Guanosine Triphosphate / Q000494:pharmacology*; D008297:Male; D010095:Oxotremorine / Q000378:metabolism; D010890:Pirenzepine / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011976:Receptors, Muscarinic / Q000187:drug effects / Q000378:metabolism*; D014316:Tritium
D011976:Receptors, Muscarinic; D014316:Tritium; D010890:Pirenzepine; D010095:Oxotremorine; D006160:Guanosine Triphosphate