Lectin‐mediated attachment assay for teratogens: Results with 32 pesticides

To gain experience in the in vitro assay of environmental teratogens, 32 pesticides and TCDD have been tested for their ability to Inhibit tumor cells attachment to polyethylene disks coated with concanavalin A. Of 25 pesticides that inhibited attachment, 23 (92%) have been reported to be teratogenic in mammals or avians. From a qualitative viewpoint, agents that inhibit attachment in vitro are very likely to be teratogenic in vivo. There was a quantitative correlation between the inhibitory activity and the lowest reported teratogenic dose in chick embryo for nine pesticides. However, no similar correlation between inhibitory concentration, in vitro, and mammalian teratogenicity was found. Presumably maternal effects of absorption, metabolism, and distribution distort the relationship between the dose administered to the mother and the concentration of teratogenic agent at target embryonic tissues. Lack of inhibition in vitro did not indicate lack of teratogenicity, as five of eight noninhibitory agents ...