Muscarinic receptor alterations following neostigmine treatment.
Male mice administered neostigmine in the drinking water a daily increasing concentrations (20-100 mg/l) for four days became tolerant to its toxicity and presented a reduced binding of [3H]quinuclidinyl benzilate ([3H]QNB) in the small intestine. An increased binding of [3H]QNB was found in the forebrains of neostigmine-treated animals. This was due to an increase in muscarinic cholinergic receptor density. Neostigmine-treated animals were also more sensitive than control to the hypothermic effect induced by oxotremorine. Dopaminergic and alpha- and beta-adrenoceptor were not affected. Administration of methylatropine together with neostigmine prevented the decrease of [3H]QNB binding in the small intestine as well as the increase in the forebrain.
D000818:Animals; D001921:Brain / Q000378:metabolism; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009388:Neostigmine / Q000494:pharmacology*; D010095:Oxotremorine / Q000494:pharmacology; D011813:Quinuclidinyl Benzilate / Q000378:metabolism; D011950:Receptors, Cholinergic / Q000187:drug effects*; D011976:Receptors, Muscarinic / Q000187:drug effects*
D011950:Receptors, Cholinergic; D011976:Receptors, Muscarinic; D009388:Neostigmine; D010095:Oxotremorine; D011813:Quinuclidinyl Benzilate