title: The effects of Western Diamondback Rattlesnake (Crotalus atrox) venom on the production of antihemorrhagins and/or antibodies in the Virginia opossum (Didelphis virginiana).
abstract: Opossums are animals that are naturally resistant to the proteolytic effects of Crotalid venoms. Opossums possess proteinase inhibitors in their sera that bind to and neutralize hemorrhagic and other proteolytic activity in many snake venoms. The proteinase inhibitors are not antibodies since they have different molecular weights (60kDa) and pI (4.2). The purpose of this study was to determine if opossums were capable of producing antibodies against venom and/or increasing the production of proteinase inhibitors (specifically antihemorrhagins). Five different venom immunization protocols were used to determine the effects of the venom in the opossums. The dosages ranged from 1mg of venom per immunization to 350mg/kg body weight of venom per immunization. The antihemorrhagic response was increased, but there is no evidence to suggest that an opossum can produce antibodies against venom. The lack of an antibody response is most likely due to the natural proteinase inhibitors clearing the venom from the opossum's body before an antibody response can occur.
authors.affiliation: Department of Biology, Texas A&M University-Kingsville, MSC 158, Kingsville, TX 78363-8202, USA.
authors.forename: Morgan R
authors.initials: MR
authors.lastname: McKeller
authors.forename: John C
authors.initials: JC
authors.lastname: Pérez
mesh_terms: D000818:Animals; D000917:Antibody Formation; D002851:Chromatography, High Pressure Liquid; D003435:Crotalid Venoms / Q000009:adverse effects* / Q000276:immunology*; D017839:Crotalus; D010450:Endopeptidases / Q000096:biosynthesis* / Q000494:pharmacology; D006470:Hemorrhage / Q000503:physiopathology / Q000517:prevention & control*; D007114:Immunization / Q000662:veterinary; D009893:Opossums / Q000276:immunology*; D011480:Protease Inhibitors / Q000032:analysis* / Q000494:pharmacology*
chemical_list: D003435:Crotalid Venoms; D011480:Protease Inhibitors; D010450:Endopeptidases; C041605:hemorrhagic proteinase IV