title: Toxic and lethal effects of ostreolysin, a cytolytic protein from edible oyster mushroom (Pleurotus ostreatus), in rodents.
abstract: Ostreolysin (Oly), an acidic, 15 kDa protein from the edible oyster mushroom (Pleurotus ostreatus), is a toxic, pore-forming cytolysin. In this paper, its toxic properties have been studied in rodents and the LD(50) in mice shown to be 1170 microg/kg. Electrocardiogram, arterial blood pressure and respiratory activity were recorded under general anaesthesia, in intact, pharmacologically vagotomised and artificially respirated rats injected with one mouse LD(50). A few seconds after intravenous Oly injection, a transient increase in arterial blood pressure was recorded, followed by a progressive fall to mid-circulatory pressure accompanied by bradicardia, myocardial ischaemia and ventricular extrasystoles. Similar changes produced by Oly were observed in vagotomised and artificially respirated animals, indicating that vagotomy and hypoxia play no primary role in toxicity. Oly induced lysis of rat erythrocytes in vitro, and probably also in vivo as indicated by the increase in serum potassium. Although direct action of the protein on the cardiomyocytes or heart circulation cannot be excluded, the hyperkalaemia resulting from the haemolytic activity probably plays an important role in its toxicity. The lethality and cardiorespiratory toxic action of Oly are thus shown to be candidates for the cause of the recorded adverse effects of oyster mushroom.
authors.affiliation: Institute of Physiology, Pharmacology and Toxicology, Veterinary Faculty, University of Ljubljana, Slovenia.
authors.forename: Monika Cecilija
authors.initials: MC
authors.lastname: Zuzek
authors.forename: Peter
authors.initials: P
authors.lastname: Macek
authors.forename: Kristina
authors.initials: K
authors.lastname: Sepcić
authors.forename: Vojteh
authors.initials: V
authors.lastname: Cestnik
authors.forename: Robert
authors.initials: R
authors.lastname: Frangez
mesh_terms: D000818:Animals; D004562:Electrocardiography; D005656:Fungal Proteins / Q000633:toxicity; D006460:Hemolysin Proteins; D006461:Hemolysis / Q000187:drug effects; D007928:Lethal Dose 50; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D020076:Pleurotus / Q000737:chemistry*
chemical_list: D005656:Fungal Proteins; D006460:Hemolysin Proteins; C461280:ostreolysin