title: Characterization of serotonergic cells in fetal heart tissue.
abstract: BACKGROUND
  We undertook this study to present biochemical and morphological characterization of serotonergic cells during fetal heart development.
  
  
  METHODS
  Wistar rats (10, 12, 16 and 20 days of gestation) were used. After obtaining the fetuses by Cesarean section, the hearts were removed and fixed for immunohistochemical assay of tryptophan-5-hydroxylase (Tph), in addition to Western blot for enzyme. Serotonin concentration and Tph were also evaluated with high-performance liquid chromatography. Results were analyzed using Mann-Whitney U test with a significance level of p <0.05.
  
  
  RESULTS
  Metachromatic cells immunoreactive for Tph were observed from day 10 of gestation. Nerve fibers were also labeled, apparently making contact with serotonergic cells. Tph activity was measurable and serotonin levels increased with gestational age. The presence of Tph protein was confirmed by Western blot on day 16.
  
  
  CONCLUSIONS
  The present results support the existence of cells located in the fetal myocardium, capable of producing serotonin whose phenotype belongs to cardiac mast cells. Their presence in this tissue strongly suggests that serotonin may play a key role in normal and abnormal development of cardiac tissue.
authors.affiliation: Unidad de Investigación Biomolecular, Hospital de Cardiología, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, México, DF, Mexico. willisga@prodigy.net.mx
authors.forename: Gabriel
authors.initials: G
authors.lastname: Manjarrez-Gutiérrez
authors.forename: Nicolás
authors.initials: N
authors.lastname: Camacho-Calderón
authors.forename: Rosalío
authors.initials: R
authors.lastname: Mercado-Camargo
authors.forename: Alfonso
authors.initials: A
authors.lastname: Boyzo-Montes de Oca
authors.forename: Alberto
authors.initials: A
authors.lastname: Arvizu-Flores
authors.forename: Jorge
authors.initials: J
authors.lastname: Hernández-Rodríguez
mesh_terms: D000818:Animals; D005260:Female; D006321:Heart / Q000196:embryology*; D008297:Male; D009206:Myocardium / Q000166:cytology* / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000096:biosynthesis*
chemical_list: D012701:Serotonin