Muscarinic receptors modulating acetylcholine release from insect synaptosomes.
1. Cholinergic synapses in the central nervous system of insects contain inhibitory muscarinic receptors whose stimulation by agonists leads to a diminished output of acetylcholine; antagonists, like atropine, facilitate acetylcholine release. 2. The receptors involved appear to be of the M2-subtype. Upon activation of presynaptic receptors a significant reduction of the intrasynaptosomal cyclic AMP level as well as a significantly increased membrane potential was observed. 3. The observed membrane hyperpolarization is apparently not a consequence of a lower cyclic AMP level, thus both effects may offer alternative or synergistical mechanisms for modulating transmitter release.
Knipper
M
M
University Hohenheim, Department of Zoophysiology, Stuttgart, West Germany.
Breer
H
H
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000109:Acetylcholine / Q000378:metabolism*; D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D003994:Bucladesine / Q000494:pharmacology / Q000031:analogs & derivatives; D002794:Choline / Q000378:metabolism; D006110:Grasshoppers / Q000378:metabolism / Q000502:physiology*; D007202:Indicators and Reagents; D008564:Membrane Potentials; D009655:Octopamine / Q000494:pharmacology; D009861:Onium Compounds; D009943:Organophosphorus Compounds; D010095:Oxotremorine / Q000494:pharmacology; D011976:Receptors, Muscarinic / Q000502:physiology*; D013574:Synaptosomes / Q000378:metabolism*
D007202:Indicators and Reagents; D009861:Onium Compounds; D009943:Organophosphorus Compounds; D011976:Receptors, Muscarinic; C002373:monobutyryl cyclic AMP; D009655:Octopamine; D015124:8-Bromo Cyclic Adenosine Monophosphate; D010095:Oxotremorine; C028955:N(6)-monobutyryl-2'-deoxycyclic adenosine monophosphate; D003994:Bucladesine; D001285:Atropine; D000262:Adenylyl Cyclases; D002794:Choline; D000109:Acetylcholine; C013289:tetraphenylphosphonium