The significance of receptor physiology for corticosterone-induced cleft palate in A/J mice

Mean plasma corticosterone levels of A/J mice rise from nonpregnant levels of 20.4 μg% to 40.6 μg% on day 11 and 167.11 μg% on day 14 of pregnancy. These changes in mean steroid levels are associated with proportionally increased diurnal swings. This suggests that the control mechanisms for diurnal swings respond in a proportional, rather than an absolute, way in regulating plasma hormone levels. Large diurnal hormone swings may be teratogenic or facilitate teratogenesis. The rules of receptor physiology may have wide application to the understanding of teratogenic risk.