Actinomycin teratogenic effects

Figure 6.22 Critical timing of the teratogenic effects of actinomycin D in the rat. The histogram shows the percentage of gross malforma- tions among surviving fetuses after a dose of 75 ng/kg, i.p. Source From Ref. 6.

The sensitive period for induction of malformations is the 5- to 14-day period in the rat and mouse and the third week to the third month in humans. This is illustrated in Figure 6.22 for the teratogen actinomycin D. The later period of fetal development, like the initial proliferative stage, is less susceptible to specific effects and an "all-or-none" type of response is usually seen, such as either death or no gross effect. 

FIGURE 7.48 Embryolethality and teratogenicity of actinomycin D. This graph shows the dose-response relationship for these two toxic effects. Data from Wilson (1965) Ann. N.Y.Acad. Sci., 123,119. 

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