Interstrain differences in the development of pyometra after estrogen treatment of rats.
This case report describes the unanticipated development of pyometra in Brown Norway rats after treatment with estrogen. Sprague Dawley and Brown Norway rats were ovariectomized and randomly assigned to treatment groups (subcutaneous implantation of either a capsule containing 20 mg 17beta-estradiol or an empty capsule, as a control). After irradiation of only the right eye, the rats were followed for several months in an attempt to determine the effects of estrogen on radiation cataractogenesis and investigate potential strain differences in this phenomenon. However, all Brown Norway rats that received estradiol treatment developed pyometra, whereas none the Sprague Dawley or control Brown Norway rats did. This case demonstrates the potential adverse effects of exogenous estrogen therapy, which are strain-specific in the rat. Caution should be taken when designing estrogen-related experiments involving Brown Norway rats and other potentially sensitive strains.
Brossia
Lisa Jane
LJ
Division of Laboratory Animal Resources, Wayne State University, Detroit, Michigan, USA. lbrossia@wayne.edu
Roberts
Christopher Sean
CS
Lopez
Jennifer T
JT
Bigsby
Robert M
RM
Dynlacht
Joseph R
JR
D000818:Animals; D002386:Cataract / Q000188:drug therapy; D004967:Estrogens / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D005123:Eye / Q000528:radiation effects; D005260:Female; D010052:Ovariectomy; D055112:Pyometra / Q000209:etiology / Q000382:microbiology / Q000662:veterinary*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012376:Rodent Diseases / Q000209:etiology* / Q000382:microbiology; D013045:Species Specificity; D014599:Uterus / Q000187:drug effects
D004967:Estrogens