title: Paeoniflorin, a major constituent of peony root, reverses muscarinic M1-receptor antagonist-induced suppression of long-term potentiation in the rat hippocampal slice.
abstract: We previously reported that paeoniflorin but not albiflorin, components of peony root, produced ameliorative effects on scopolamine-induced spatial cognitive impairment in rats. In this study, we examined the effects of paeoniflorin and muscarinic receptor antagonists on long-term potentiation (LTP) of population spike recorded from the CA1 region of rat hippocampal slices. Bath applications of an M1- and M2-receptor antagonist scopolamine and a selective M1-receptor antagonist pirenzepine, at a concentration of 10 microM, significantly suppressed LTP, whereas AF-DX116, a selective M2-receptor antagonist, failed to affect it. Paeoniflorin (0.1-1 microM), which alone was ineffective on LTP induction, significantly reversed the suppressive effects of scopolamine and pirenzepine (10 microM). In contrast, albiflorin (0.1- 1 microM) had no effect on the scopolamine-induced LTP suppression. These results suggest that paeoniflorin reversal of the muscarinic M1-receptor-mediated inhibition of LTP may be implicated in the ameliorative effect of paeoniflorin on spatial cognitive impairment caused by cholinergic dysfunction.
authors.affiliation: Department of Pharmacology, Institute of Natural Medicine, Toyama Medical and Pharmaceutical University, Sugitani, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Tabata
authors.forename: K
authors.initials: K
authors.lastname: Matsumoto
authors.forename: H
authors.initials: H
authors.lastname: Watanabe
mesh_terms: D008455:(4-(m-Chlorophenylcarbamoyloxy)-2-butynyl)trimethylammonium Chloride / Q000494:pharmacology; D000818:Animals; D001565:Benzoates; D001952:Bridged-Ring Compounds / Q000494:pharmacology; D003071:Cognition / Q000187:drug effects; D005960:Glucosides / Q000494:pharmacology*; D006624:Hippocampus / Q000187:drug effects* / Q000502:physiology; D017774:Long-Term Potentiation / Q000187:drug effects*; D008297:Male; D039821:Monoterpenes; D018727:Muscarinic Antagonists / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D043643:Receptor, Muscarinic M1; D011976:Receptors, Muscarinic / Q000187:drug effects*; D006027:Glycosides
chemical_list: D008455:(4-(m-Chlorophenylcarbamoyloxy)-2-butynyl)trimethylammonium Chloride; D001565:Benzoates; D001952:Bridged-Ring Compounds; D005960:Glucosides; D039821:Monoterpenes; D018727:Muscarinic Antagonists; D043643:Receptor, Muscarinic M1; D011976:Receptors, Muscarinic; C015423:peoniflorin; D006027:Glycosides; C014959:albiflorin