title: Participation of cholinergic pathways in α-hederin-induced contraction of rat isolated stomach strips.
abstract: The dry extract of Hedra helix leaves and its main active compounds, predominantly α-hederin and hederacoside C, has been traditionally believed to act spasmolytic. However, it has been recently proved that both, the extract of ivy and triterpenoid saponins, exhibit strong contractile effect on rat isolated stomach smooth muscle strips. It turned out that the most potent contractile agent isolated from the extract of ivy leaves is α-hederin. Thus, it seems reasonable to estimate the mechanism of the contractile effect of this saponin. The presented study was aimed at verifying the participation of cholinergic pathways (muscarinic and nicotine receptors) in α-hederin-induced contraction. The experiments were carried out on rat isolated stomach corpus and fundus strips under isotonic conditions. The preparations were preincubated with either atropine or hexamethonium and then exposed to α-hederin. All results are expressed as the percentage of the response to acetylcholine - a reference contractile agent. The obtained results revealed that the pretreatment of isolated stomach strips (corpus and fundus) with atropine neither prevented nor remarkably reduced the reaction of the preparations to α-hederin. Similarly, if the application of saponin was preceded by the administration of hexamethonium, the strength of the contraction of stomach fundus strips induced by α-hederin was not modified. Concluding, it can be assumed that the cholinergic pathways do not participate in α-hederin-evoked contraction of rat isolated stomach preparations.
authors.affiliation: Division of Pharmacology and Toxicology, Department of Preclinical Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland. marta_mendel@sggw.pl
authors.forename: M
authors.initials: M
authors.lastname: Mendel
authors.forename: M
authors.initials: M
authors.lastname: Chłopecka
authors.forename: N
authors.initials: N
authors.lastname: Dziekan
authors.forename: W
authors.initials: W
authors.lastname: Karlik
authors.forename: M
authors.initials: M
authors.lastname: Wiechetek
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D027481:Araliaceae / Q000737:chemistry*; D001285:Atropine / Q000494:pharmacology; D018678:Cholinergic Agents / Q000494:pharmacology*; D018738:Hexamethonium / Q000494:pharmacology; D008297:Male; D018727:Muscarinic Antagonists / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects* / Q000502:physiology; D018733:Nicotinic Antagonists / Q000494:pharmacology; D009828:Oleanolic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves; D051381:Rats; D017208:Rats, Wistar; D011976:Receptors, Muscarinic / Q000378:metabolism; D011978:Receptors, Nicotinic / Q000378:metabolism; D012016:Reference Values; D012503:Saponins / Q000494:pharmacology*; D015398:Signal Transduction; D013270:Stomach / Q000187:drug effects* / Q000502:physiology
chemical_list: D018678:Cholinergic Agents; D018727:Muscarinic Antagonists; D018733:Nicotinic Antagonists; D010936:Plant Extracts; D011976:Receptors, Muscarinic; D011978:Receptors, Nicotinic; D012503:Saponins; C010177:beta-hederin; D018738:Hexamethonium; D009828:Oleanolic Acid; D001285:Atropine; D000109:Acetylcholine