To better define the mechanisms by which zinc (Zn) deficiency influences periconceptional development, we examined the effects of this developmental insult on uterine estrogen metabolism. CD-1 mice were assigned to 1 of 3 groups (Low Zn, LZ; Control, C; or Replete, R) and fed either a low Zn (< or = 0.3 microgram Zn/g) or control diet (47 micrograms Zn/g) 5 days prior to gestation day (GD) 0 and continuing up to GD 4 during early pregnancy. Mice in the R group were fed the low Zn diet until GD 1 after which they were fed the control diet. Uterine 3H-estradiol binding in vivo was measured on GD 2, GD 3, and GD 4. Binding was similar among groups on GD 2 and GD 3, but was lower on GD 4 in LZ mice than in C and R mice (61% of control value). On GD 4, uterine 3H-estradiol binding in vitro was measured and was lower in LZ mice than in C and R mice (63-74% of control values); the reduction in binding was due to lower receptor number. Thus, Zn deficiency can result in a reduction in uterine estradiol receptors and estradiol binding.