title: Inhibitory effect of cimetidine on graft survival of allotransplanted rats submitted to an active-passive enhancement protocol.
abstract: The objective of the present study was to determine whether cimetidine, a type-2 histamine receptor antagonist, inhibits the immunological enhancement of allografted rats achieved by treatment with donor antigen plus anti-donor antibody. Groups of rats submitted to this active-passive enhancement protocol and treated ip with 30 (APEC 30; Group I; N = 4) or 60 (APEC 60; Group II; N = 8) mg/day cimetidine for 14 days had a significantly shorter graft survival (20.2 +/- 5.1 and 11.1 +/- 2.6 days, respectively) than the control group (animals submitted to the enhancement protocol and killed on day 72 after transplant when the graft was beating normally; APE; Group III; N = 6; P less than 0.05). On the other hand, these animals had a significantly longer graft survival than rats allotransplanted but not treated for enhancement (ALLO; Group V; N = 5; 8.2 +/- 0.8 days). The surgical control, consisting of isotransplanted animals, had a long-term survival (ISO; Group VI; N = 6; rats killed 120 days after transplant with the graft beating normally). Animals treated with cimetidine, but not submitted to the enhancement protocol (AC 60; Group IV, N = 4) had a significantly shorter graft survival (6.25 +/- 0.5) than the allotransplanted animals (Group V). These results indicate inhibition of the suppressor mechanisms which participate in this type of immunological enhancement.
authors.affiliation: Laboratório de Immunogenética e Transplante Experimental, Faculdade de Medicina, Universidade de São Paulo, Brasil.
authors.forename: M M
authors.initials: MM
authors.lastname: Tanji
authors.forename: M
authors.initials: M
authors.lastname: Cianga-Tanji
authors.forename: R
authors.initials: R
authors.lastname: Kaneno
authors.forename: M N
authors.initials: MN
authors.lastname: Sato
authors.forename: A J
authors.initials: AJ
authors.lastname: Duarte
mesh_terms: D000818:Animals; D000941:Antigens / Q000008:administration & dosage; D002927:Cimetidine / Q000494:pharmacology*; D006082:Graft Enhancement, Immunologic / Q000379:methods*; D006085:Graft Survival / Q000187:drug effects*; D007114:Immunization; D008214:Lymphocytes / Q000276:immunology; D008297:Male; D051381:Rats; D011914:Rats, Inbred BN; D011917:Rats, Inbred Lew; D014181:Transplantation Immunology
chemical_list: D000941:Antigens; D002927:Cimetidine