The use of in vitro procedures in teratology.

The capabilities of investigators in the fields of teratology and toxicology are greatly enhanced by the use of tissue culture procedures in unraveling the mechanisms of drug action. Techniques currently available for the culture of postimplantation mammalian embryos permit evaluation of their metabolic responses to potential teratogens even when the length of time embryos survive and develop in culture is too short to allow a conventional teratologic survey of malformations. A simple procedure for culturing mouse embryos during early organogenetic stages is described in this report that will be of value to teratologists; it avoids the requirements of special glassware and equipment by using ordinary capped test tubes which are rotated tomaintain and efficient nutritional and gaseous evnironment. Some studies concucted with this procedure to monitor the metabolism of embryo during the first 24 h of culture are summarized. Another aspect of tissue culture, organ culture, provides further manipulative capability by which embryonic organs can be maintained for long periods of time during which they develop and differentiate to an extent that their morphological and biochemical responses to a teratogen can usually be made. Comparative effects of several teratogenic agents and the relative concentration of each that produces a similar degree of response are summarized. It is concluded that organs are more sensitive to teratogens in culture than they are in vivo, and that different teratogens possess enough specificity to isolate their simple growth-retarding effect from the role they play in distrubing other specific developmental events.