Synthetic flavonoids cross the placenta in the rat and are found in
fetal brain..
Elst, J. P. Schr[umlaut]uder-Van Der, D. Van Der Heide, H. Rokos, G.
Morreale De Escobar, and J. K[umlaut]uhrle.
Human and Animal Physiology, Agricultural University, Wageningen,
The Netherlands, Henning Berlin, Berlin, Germany; Instituto de
Investigaciones Biom[umlaut]adicas, Consejo Superior de
Investigaciones Cientficas, Madrid, Spain, Klinische Forschergruppe,
Medizinische Poliklinik, Universit[grave]et Worzburg, Germany
APStracts 4:0231E, 1997.
The synthetic flavonoid EMD 49209 is a potent inhibitor of the in vivo
and in vitro binding of T4 (thyroxine) to transthyretin (TTR). We
studied the distribution of [125I]-EMD 49209 in maternal tissues,
intestinal contents and fetal tissues in rats that were 20 days
pregnant (from 1 to 24 hrs after i.v. injection). The % 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 % dose of EMD increased with
time; after 24 hours it contained 17 % of the EMD. The flavonoid was
found in all fetal tissues investigated, also in the fetal brain.
Simce 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 T4 in the fetal compartment.
Received 24 March 1997; accepted in final form 9 October 1997.
APS Manuscript Number E135-7.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1997 The American Physiological Society.
Published in APStracts on 29 October 1997