Effect of vitamin D3 treatment in the neonatal or adolescent age (hormonal imprinting) on the thymic glucocorticoid receptor of the adult male rat

Single neonatal treatment with 25 mu g vitamin D-3 significantly decreased the thymic glucocorticoid receptor density (B-max) of 6-week-old male rats. In females, a similar treatment did not cause any changes. Single vitamin D-3 treatment (50 mu g) during adolescence (i.e. 6-week-old animals) significantly increased the glucocorticoid receptor density in adult (10-week-old) males. No significant changes in receptor affinity (K-d) could be observed. Considering that in earlier experiments similar neonatal treatments influenced bone mineral mass and sexual behavior, the hormonal imprinting effect of vitamin D-3 and its harmful effect on the development of other members of the steroid receptor superfamily, seems to be unquestionable. Copyright (C) 2000 S. Karger AG, Basel.