Characterization of serotonergic cells in fetal heart tissue.
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.
Manjarrez-Gutiérrez
Gabriel
G
Unidad de Investigación Biomolecular, Hospital de Cardiología, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, México, DF, Mexico. willisga@prodigy.net.mx
Camacho-Calderón
Nicolás
N
Mercado-Camargo
Rosalío
R
Boyzo-Montes de Oca
Alfonso
A
Arvizu-Flores
Alberto
A
Hernández-Rodríguez
Jorge
J
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*
D012701:Serotonin