Portal de Periódicos da CAPES

Synthetic flavonoids cross the placenta in the rat and are found in fetal brain

1998; American Physiological Society; Volume: 274; Issue: 2 Linguagem: Inglês

10.1152/ajpendo.1998.274.2.e253

1522-1555

Janny P. Schröder-van der Elst, D. van der Heide, Hartmut Rokos, Gabriella Morreale de Escobar, Josef Köhrle,

Estrogen and related hormone effects

The synthetic flavonoid EMD-49209 is a potent inhibitor of the in vivo and in vitro binding of thyroxine (T 4 ) to transthyretin (TTR). We studied the distribution of 125 I-labeled EMD-49209 in maternal tissues, intestinal contents, and fetal tissues in rats that were 20 days pregnant (from 1 to 24 h after intravenous injection). The percent dose of EMD decreased quickly with time. In maternal brain no radioactive flavonoid could be detected. EMD was excreted very rapidly from the intestines. In the fetal compartment the percent dose of EMD increased with time; after 24 h it contained 17% of the EMD. The flavonoid was found in all fetal tissues investigated and also in the fetal brain. Because TTR concentrations are high in the fetal rat, especially in the brain, the transfer of flavonoid to the fetal brain might be linked to TTR expression. The presence of flavonoid in the fetal brain raises the possibility of an essential interference of flavonoids with the availablity of T 4 in the fetal compartment.