title: Alterations in the ultrastructure of cardiac autonomic nervous system triggered by crotoxin from rattlesnake (Crotalus durissus cumanensis) venom.
abstract: This study explored the toxic effects of crotoxin isolated from Crotalus durissus cumanensis venom on the ultrastructure of mice cardiac autonomic nervous system. Mice were intravenously injected with saline (control group) and crotoxin diluted in saline venom (study group) at a dose of 0.107 mg/kg mouse body weight. Samples from the inter-ventricular septum were prepared for electron microscopy after 6 h (G1), 12 h (G2), 24 h (G3) and 48 h (G4). The G1 group showed some cardiomyocyte with pleomorphic mitochondria. Capillary swollen walls, nerve cholinergic endings with depleted acetylcholine vesicles in their interior and other depletions were observed. A space completely lacking in contractile elements was noticed. The G2 group demonstrated a myelinic figure, a subsarcolemic region with few myofibrils and nervous cholinergic terminal with scarce vacuoles in their interior. The G3 group demonstrated a structure with a depleted axonic terminal, mitochondrias varying in size and enhanced electron density. In addition, muscular fibers with myofibrillar structure disorganization, a depleted nervous structure surrounded by a Schwann cell along with an abundance of natriuretic peptides, were seen. An amyelinic terminal with depleted Schwann cell and with scarce vesicles was also observed. Finally, axonic lysis with autophagic vacuoles in their interior and condensed mitochondria was observed in the G4 group. This work describes the first report of ultrastructural damage caused by crotoxin on mice cardiac autonomic nervous system.
authors.affiliation: Sección de Inmunoquímica del Instituto de Medicina Tropical Universidad Central de Venezuela, Apartado 47423, Caracas 1041, Venezuela.
authors.forename: Miguelina
authors.initials: M
authors.lastname: Hernández
authors.forename: Héctor
authors.initials: H
authors.lastname: Scannone
authors.forename: Héctor J
authors.initials: HJ
authors.lastname: Finol
authors.forename: Maria E
authors.initials: ME
authors.lastname: Pineda
authors.forename: Irma
authors.initials: I
authors.lastname: Fernández
authors.forename: Alba M
authors.initials: AM
authors.lastname: Vargas
authors.forename: María E
authors.initials: ME
authors.lastname: Girón
authors.forename: Irma
authors.initials: I
authors.lastname: Aguilar
authors.forename: Alexis
authors.initials: A
authors.lastname: Rodríguez-Acosta
mesh_terms: D000109:Acetylcholine / Q000378:metabolism; D000818:Animals; D001341:Autonomic Nervous System / Q000187:drug effects* / Q000648:ultrastructure*; D002196:Capillaries / Q000187:drug effects / Q000648:ultrastructure; D003331:Coronary Vessels / Q000187:drug effects / Q000648:ultrastructure; D017839:Crotalus; D003439:Crotoxin / Q000737:chemistry / Q000633:toxicity*; D006321:Heart / Q000294:innervation*; D008297:Male; D051379:Mice; D046529:Microscopy, Electron, Transmission; D008929:Mitochondria, Heart / Q000187:drug effects / Q000648:ultrastructure; D009046:Motor Neurons / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000648:ultrastructure; D009411:Nerve Endings / Q000187:drug effects / Q000648:ultrastructure; D012519:Sarcoplasmic Reticulum / Q000187:drug effects / Q000648:ultrastructure; D012583:Schwann Cells / Q000187:drug effects / Q000648:ultrastructure
chemical_list: D003439:Crotoxin; D000109:Acetylcholine