title: Teratogenic effects of bis-diamine on the developing myocardium.
abstract: BACKGROUND
  Bis-diamine induces conotruncal anomalies and disproportional ventricular development in rat embryos when administered to the mother. To evaluate the mechanisms of disproportional ventricular development in the anomalous heart, we analyzed the morphology of the embryonic heart and investigated cardiomyocytic DNA synthesis and apoptosis.
  
  
  METHODS
  A single dose of 200 mg of bis-diamine was administered to pregnant rats Wistar on day 9.5 of pregnancy. The embryos were removed on each embryonic day from 10.5 to 18.5. Expression of cardiotrophin-1 and hepatocyte growth factor was investigated on the sections, and cardiotrophin-1, hepatocyte growth factor and myocyte enhancer factor 2 mRNA expression was examined by reverse transcriptase-polymerase chain reaction. Myocardial DNA synthesis was investigated using 5-bromo-2'-deoxyuridine and the labeling index was calculated for each heart. Apoptosis was also analyzed using TUNEL reaction and electrophoresis of DNA fragmentation.
  
  
  RESULTS
  The embryos treated with bis-diamine had conotruncal anomalies associated with thin left ventricular wall in the later stage. The labeling index on embryonic day 15.5 and 16.5 was significantly lower than those in the controls. Hepatocyte growth factor and cardiotrophin-1 mRNA expression was upregulated on embryonic day 12.5 and 15.5 in bis-diamine-treated hearts. Fewer apoptotic cells were detected in the hearts of bis-diamine-treated embryos than in control hearts from embryonic day 14.5 to 16.5.
  
  
  CONCLUSIONS
  The ventricular disproportion in the bis-diamine-treated heart may be caused by the early myocardial differentiation delay and poor proliferation and reduced apoptosis associated with anomalous circulatory condition in the later stage.
authors.affiliation: Department of Pediatrics, Shiga University of Medical Science, Seta, Otsu, Shiga 520-2192, Japan. cxq07667@nifty.com
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Okamoto
authors.forename: Masao
authors.initials: M
authors.lastname: Nakagawa
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Fujino
authors.forename: Setsuko
authors.initials: S
authors.lastname: Nishijima
authors.forename: Takashi
authors.initials: T
authors.lastname: Hanato
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Narita
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Takeuchi
authors.forename: Kyoko
authors.initials: K
authors.lastname: Imanaka-Yoshida
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001483:Base Sequence; D001973:Bromodeoxyuridine; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D017931:DNA Primers; D003959:Diamines / Q000633:toxicity*; D006321:Heart / Q000187:drug effects* / Q000196:embryology; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013723:Teratogens / Q000633:toxicity*
chemical_list: D017931:DNA Primers; D003959:Diamines; D013723:Teratogens; D001973:Bromodeoxyuridine