Placental transport of brevetoxin-3 in CD-1 mice

Abstract

The purpose of this study was to examine the distribution of brevetoxin-3 administered to pregnant dams and to determine the extent of placental transport to fetuses. Twenty-nine pregnant CD-1 mice were administered 3 H-brevetoxin-3 (~1.3 μCi/animal; ~2.8 μg compound/kg) by intratracheal instillation on one of gestational days 15-18. Groups of four or five dams were killed at selected times through 48 h post dosing. Four pregnant dams were administered 3 H-brevetoxin-3 on gestational day 15 or 16 via osmotic minipump to provide continuous delivery of compound (~0.13 μCi, 7.5 ng compound/day) over a 72-h period after which the dams and fetuses were d. Brevetoxinassociated radioactivity was detected in placentas and fetuses within 0.5 h of intratracheal administration. Concentrations of brevetoxin equivalents in fetuses were approximately 0.3 ng/g throughout the 48-h post dosing, resulting in a calculated dose to fetuses of 19 ng/g-h. Following brevetoxin infusion, concentration of brevetoxin equivalents in fetuses was 0.1 ng/g, lower than that present in most maternal tissues. Results demonstrated placental transport of brevetoxin or its metabolites following maternal acute exposure and repeated low-dose exposure. The consequences of these findings for pregnant women exposed to brevetoxins by inhalation or ingestion remain to be determined.

Review of Florida red tide and human health effects

“…Long term exposures of rodents to aerosolized brevetoxins have demonstrated immune dysfunction, including delay of viral clearance and possible enhancement of the pathogenicity of influenza A (J Benson, Lovelace Respiratory Research Institute, personal communication). Rodent studies have also been important in demonstrating that brevetoxins delivered in aerosols are not teratogenic in multi-generational exposure studies (Benson et al, 2006). …”

Chemical Defenses: From Compounds to Communities

“…Fish remained healthy while brevetoxin accumulated in tissues from a food source, and thus they served as a mechanism for trophic transfer of toxins (Flewelling et al, 2005). Recent evidence suggests that brevetoxins and their metabolites may be transported through the placenta from mother to offspring in mammals, although the implications of this finding are still inconclusive (Benson et al, 2006). Abnormalities have been observed in the development of fish embryos after the eggs were exposed to PbTx-1.…”

Effects of in vitro Brevetoxin Exposure on Apoptosis and Cellular Metabolism in a Leukemic T Cell Line (Jurkat)

“…Blood lipoproteins bind brevetoxins [33,34], which increases systemic distribution as well as the ability of toxin to enter cells. Placental transport of PbTx-3 also occurs [35]. These observations lend support to the hypothesis that brevetoxin exposure has the capacity to impact the immune system in that blood is continuously in contact with tissues and is host to effector immune cells.…”