title: Upregulation of estrogen receptor-alpha expression in rabbit cardiac allograft.
abstract: Estrogen receptor (ER) expression has been detected in different tissues, and estradiol-17beta treatment protects against experimental transplant arteriosclerosis. In this study, ER-alpha expression in the rabbit hearts and attached aortas before and after cardiac-aorta allograft transplantation was examined. Ten male New Zealand White rabbits were transplanted with cardiac-aorta allografts from male Dutch Belted rabbits. This transplant arteriosclerosis model uses a 0.5% cholesterol diet and immunosuppression with cyclosporin A (10 mg . kg-1 . d-1) until euthanatization 42 days later. The cardiac grafts with the attached aorta were harvested. Strong staining of ER-alpha protein was shown in the coronary arteries of the cardiac allografts by immunohistochemistry with the use of a mouse anti-human ER-alpha monoclonal antibody (ID5). In contrast, both the nongrafted hearts of the recipients and donor hearts expressed only weak staining. RNase protection assay with the use of a 32P-labeled ER-alpha antisense riboprobe (pOR 300) proved that the basal expression of ER-alpha mRNA is similar in the nongrafted aorta of both recipients and donors. A marked increase of ER-alpha mRNA was observed in the allograft aorta compared with the nongrafted aorta (289+/-69%, P<0. 02) by reverse transcription and polymerase chain reaction. The DNA sequence analysis confirmed that the polymerase chain reaction-amplified fragment corresponded to ER-alpha. This is the first observation of ER-alpha upregulation in the allograft vasculature and may relate to the allograft cardiovascular protective effects of estrogen.
authors.affiliation: Department of Surgery, Georgetown University Medical Center, Washington, DC 20007, USA.
authors.forename: H
authors.initials: H
authors.lastname: Lou
authors.forename: M B
authors.initials: MB
authors.lastname: Martin
authors.forename: A
authors.initials: A
authors.lastname: Stoica
authors.forename: P W
authors.initials: PW
authors.lastname: Ramwell
authors.forename: M L
authors.initials: ML
authors.lastname: Foegh
mesh_terms: D000818:Animals; D005786:Gene Expression Regulation; D016027:Heart Transplantation; D006801:Humans; D008297:Male; D051379:Mice; D012333:RNA, Messenger / Q000032:analysis; D011817:Rabbits; D011960:Receptors, Estrogen / Q000032:analysis* / Q000235:genetics; D014184:Transplantation, Homologous; D015854:Up-Regulation
chemical_list: D012333:RNA, Messenger; D011960:Receptors, Estrogen