title: Atrioventricular valvular angiectasis in Sprague-Dawley rats.
abstract: Subendothelial heart valve angiectasis has been reported in cows, dogs, pigs, rats, mice, and in human fetuses and newborns. We observed a high incidence (62 in 208 animals examined) of spontaneous angiectasis on the atrioventricular (AV) valves in 10- to 40-week-old Sprague-Dawley rats. The angiectasis was observed predominately on the septal cusp of the right AV valve and located near the AV ostium in 57 of 62 animals. Of the remaining 5 valvular angiectases, 2 were present on the parietal cusp of the right AV valve and 3 were on the left AV valve. The angiectases were single or multiple, ranging from 40 to 300 microm in diameter and were characterized by light microscopy as blood-filled dilatations lined by endothelium. Spontaneously occurring abnormalities in normal laboratory animals, such as the spontaneous valvular angiectasis reported here, need to be differentiated from drug-related lesions.
authors.affiliation: Department of Pathology, Drug Safety Evaluation, Pharmaceutical Research Institute, Bristol-Myers Squibb Company, Syracuse, NY 13221-4755, USA. hengsheng.fang@bms.com
authors.forename: H
authors.initials: H
authors.lastname: Fang
authors.forename: P C
authors.initials: PC
authors.lastname: Howroyd
authors.forename: A M
authors.initials: AM
authors.lastname: Fletcher
authors.forename: R W
authors.initials: RW
authors.lastname: Diters
authors.forename: J
authors.initials: J
authors.lastname: Woicke
authors.forename: V G
authors.initials: VG
authors.lastname: Sasseville
authors.forename: C L
authors.initials: CL
authors.lastname: Bregman
authors.forename: W J
authors.initials: WJ
authors.lastname: Freebern
authors.forename: S K
authors.initials: SK
authors.lastname: Durham
authors.forename: M G
authors.initials: MG
authors.lastname: Mense
mesh_terms: D000818:Animals; D005260:Female; D006349:Heart Valve Diseases / Q000473:pathology / Q000662:veterinary*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012376:Rodent Diseases / Q000473:pathology*; D014652:Vascular Diseases / Q000473:pathology / Q000662:veterinary*