title: Vitamin K deficiency syndromes in warfarin-resistant brown rats (Rattus norvegicus).
abstract: Resistance to the anticoagulant rodenticide warfarin and an increased vitamin K requirement appear to be pleiotropic effects of the gene Rw2. A comparison of pup mortality in F2 (Rw1Rw2 x Rw1Rw2) and backcross (Rw1Rw2 x Rw1Rw1 or reciprocal) matings of wild brown rats in the laboratory revealed significantly greater losses in the F2 litters at 4-8 weeks of age. Some deaths could be attributed directly to haemorrhage resulting from vitamin K deficiency. A newborn warfarin-resistant rat from an F2 litter showed bleeding from the umbilicus and the anus, and died from internal haemorrhage at 18 weeks of age. Another warfarin-resistant male rat dying at the same age had a grossly enlarged skull.
mesh_terms: D000483:Alleles; D000818:Animals; D000831:Animals, Newborn / Q000235:genetics; D004351:Drug Resistance; D005260:Female; D008297:Male; D009026:Mortality; D011247:Pregnancy; D051381:Rats / Q000235:genetics*; D012376:Rodent Diseases / Q000235:genetics; D014813:Vitamin K Deficiency / Q000235:genetics / Q000662:veterinary*; D014859:Warfarin
chemical_list: D014859:Warfarin