title: Synergistic effects of malononitrilamides (FK778, FK779) with tacrolimus (FK506) in prevention of acute heart and kidney allograft rejection and reversal of ongoing heart allograft rejection in the rat.
abstract: BACKGROUND
  The effects of tacrolimus (FK506) and malononitrilamides (MNA) (FK778 and FK779) monotherapy and combination therapy were examined in prevention of acute heart and kidney allograft rejection and reversal of ongoing acute heart allograft rejection in the rat.
  
  
  METHODS
  Brown Norway (RT1n)-to-Lewis (RT11) and ACI (RT1a)-to-Lewis (RT11) combinations were used, respectively, for heart and kidney transplantation models. Immunosuppressants were administered orally from day 1 to day 14 for preventing acute rejection and from day 4 to day 34 after transplantation for the reversal of ongoing acute rejection.
  
  
  RESULTS
  In the prevention of acute heart rejection model, recipient rats treated with monotherapy of tacrolimus or MNA (FK778, FK779) showed a dose-related prolongation of mean survival time (MST) compared with naive control rats (P<0.01). The mean survival time in combination therapy of tacrolimus (FK506) and FK778 indicated that an additive to synergistic interaction was produced when compared with the respective monotherapies (combination index [CI]=0.631-1.022). These results were reproducible with tacrolimus and FK779 combination therapy (CI=0.572-0.846). Furthermore, similar results were also found in the prevention of acute kidney allograft rejection in the rat (CI=0.137-0.516). In the reversal of ongoing acute heart allograft rejection, combination therapy of tacrolimus and FK778 demonstrated a strong synergistic interaction (CI=0.166-0.970) compared with monotherapy of tacrolimus or FK778.
  
  
  CONCLUSIONS
  Combination therapy of tacrolimus and MNA (FK778, FK779) produces synergistic effects in prevention of acute heart and kidney rejection and reversal of ongoing heart allograft rejection in the rat.
authors.affiliation: Laboratory of Experimental Surgery, Research Center of CHUM, Notre-Dame Hospital, University of Montreal, Montreal, Quebec, Canada.
authors.forename: Kupa K
authors.initials: KK
authors.lastname: Bilolo
authors.forename: Jun
authors.initials: J
authors.lastname: Ouyang
authors.forename: Xiang
authors.initials: X
authors.lastname: Wang
authors.forename: Shengyun
authors.initials: S
authors.lastname: Zhu
authors.forename: Wenlei
authors.initials: W
authors.lastname: Jiang
authors.forename: Shijie
authors.initials: S
authors.lastname: Qi
authors.forename: Dasheng
authors.initials: D
authors.lastname: Xu
authors.forename: Marie J
authors.initials: MJ
authors.lastname: Hebert
authors.forename: Ihor
authors.initials: I
authors.lastname: Bekersky
authors.forename: William E
authors.initials: WE
authors.lastname: Fitzsimmons
authors.forename: Huifang
authors.initials: H
authors.lastname: Chen
mesh_terms: D000208:Acute Disease; D000480:Alkynes; D000818:Animals; D004357:Drug Synergism; D006084:Graft Rejection / Q000188:drug therapy / Q000473:pathology / Q000517:prevention & control*; D016027:Heart Transplantation; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D007555:Isoxazoles / Q000737:chemistry / Q000494:pharmacology*; D007668:Kidney / Q000473:pathology / Q000502:physiology / Q000601:surgery; D016030:Kidney Transplantation; D008297:Male; D009206:Myocardium / Q000473:pathology; D009570:Nitriles; D051381:Rats; D011912:Rats, Inbred ACI; D011914:Rats, Inbred BN; D011917:Rats, Inbred Lew; D016559:Tacrolimus / Q000494:pharmacology*; D014184:Transplantation, Homologous
chemical_list: D000480:Alkynes; D007166:Immunosuppressive Agents; D007555:Isoxazoles; D009570:Nitriles; C115284:2-cyano-3-hydroxy-N-(4-(trifluoromethyl)phenyl)-2-hepten-6-ynamide; D016559:Tacrolimus