Embryotoxicity of polychlorinated biphenyls (PCBS) for preimplantation embryos.
In a previous study oral administration of a commercial PCB mixture (Aroclor 1,260) to female rabbits (4 mg/kg b.wt. for 14 weeks) resulted in a significant accumulation of PCBs in 6-d-old blastocysts and increased preimplantation embryo mortality (1). In the present study, the direct toxicity of PCBs on preimplantation rabbit embryos was investigated during in vitro culture. One-day-old cleavage stages and 3-d-old rabbit morulae were cultured in BSM II medium supplemented with 1.5% BSA in a reduced oxygen concentration of 5% O2. They were exposed to 50, 5, or 0.5 microgram Aroclor 1,260/mL culture medium for 24 h. PCB (50 micrograms) led to a complete degeneration of the exposed embryos. Following exposure to 5 micrograms only 16% of the morulae developed into blastocysts. The others were either arrested in the morulae stage or were degenerated. Cell proliferation of the nondegenerated embryos was approximately 20% of that of corresponding control embryos. Compared with nonexposed controls, addition of 0.5 microgram PCB/mL showed either no or only a slight impairment of development. Preliminary embryo transfer experiments showed that morulae exposed to 5 micrograms PCB with clear signs of degeneration after 24 h in vitro culture were able to implant. Aroclor 1,260 is embryotoxic in a dose-dependent manner in cultured rabbit preimplantation embryos.
Lindenau
A
A
Department of Anatomy and Cell Biology, Martin Luther University, Halle (Saale), Germany.
Fischer
B
B
D000818:Animals; D001140:Aroclors / Q000633:toxicity*; D001755:Blastocyst / Q000187:drug effects*; D002455:Cell Division / Q000187:drug effects; D046508:Culture Techniques; D004624:Embryo Transfer; D005260:Female; D009024:Morphogenesis / Q000187:drug effects; D009028:Morula / Q000187:drug effects; D011247:Pregnancy; D011817:Rabbits
D001140:Aroclors; C026987:aroclor 1260