title: Hemorrhage Caused by Snake Venom Metalloproteinases: A Journey of Discovery and Understanding.
abstract: The historical development of discoveries and conceptual frames for understanding the hemorrhagic activity induced by viperid snake venoms and by hemorrhagic metalloproteinases (SVMPs) present in these venoms is reviewed. Histological and ultrastructural tools allowed the identification of the capillary network as the main site of action of SVMPs. After years of debate, biochemical developments demonstrated that all hemorrhagic toxins in viperid venoms are zinc-dependent metalloproteinases. Hemorrhagic SVMPs act by initially hydrolyzing key substrates at the basement membrane (BM) of capillaries. This degradation results in the weakening of the mechanical stability of the capillary wall, which becomes distended owing of the action of the hemodynamic biophysical forces operating in the circulation. As a consequence, the capillary wall is disrupted and extravasation occurs. SVMPs do not induce rapid toxicity to endothelial cells, and the pathological effects described in these cells in vivo result from the mechanical action of these hemodynamic forces. Experimental evidence suggests that degradation of type IV collagen, and perhaps also perlecan, is the key event in the onset of microvessel damage. It is necessary to study this phenomenon from a holistic, systemic perspective in which the action of other venom components is also taken into consideration.
authors.affiliation: Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José 11501-2060, Costa Rica. jose.gutierrez@ucr.ac.cr.
authors.forename: José María
authors.initials: JM
authors.lastname: Gutiérrez
authors.affiliation: Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José 11501-2060, Costa Rica. teresa.escalante@ucr.ac.cr.
authors.forename: Teresa
authors.initials: T
authors.lastname: Escalante
authors.affiliation: Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José 11501-2060, Costa Rica. alexandra.rucavado@ucr.ac.cr.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Rucavado
authors.affiliation: Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José 11501-2060, Costa Rica. cristina.herreraarias@gmail.com.|Facultad de Farmacia, Universidad de Costa Rica, San José 11501-2060, Costa Rica. cristina.herreraarias@gmail.com.
authors.forename: Cristina
authors.initials: C
authors.lastname: Herrera
mesh_terms: D000818:Animals; D001485:Basement Membrane / Q000187:drug effects; D042783:Endothelial Cells / Q000187:drug effects / Q000473:pathology; D006470:Hemorrhage / Q000139:chemically induced* / Q000473:pathology; D008666:Metalloendopeptidases / Q000633:toxicity*; D055806:Microvessels / Q000187:drug effects / Q000473:pathology; D030162:Reptilian Proteins / Q000633:toxicity*; D014757:Viper Venoms / Q000201:enzymology*
chemical_list: D030162:Reptilian Proteins; D014757:Viper Venoms; D008666:Metalloendopeptidases; C069317:hemorrhagic metalloproteinase
keywords: basement membrane; capillary vessels; hemorrhage; metalloproteinases; snake venom; type IV collagen; viperids