EPIDERMAL GROWTH-FACTOR RECEPTOR LEVELS IN REPRODUCTIVE-ORGANS OF FEMALE MICE EXPOSED NEONATALLY TO DIETHYLSTILBESTROL

Binding of epidermal growth factor (EGF) to membrane preparations of v agina, uterus, ovary, oviduct, and liver was examined in mice treated neonatally with diethylstilbestrol (DES) and compared with that in unt reated mice. Binding in the vagina (12.5 +/- 0.73 fmol/mg protein) was somewhat higher than in the uterus (8.0 +/- 0.34 fmol/mg protein). Le vel of specific binding was of the order: liver (18.4 +/- 1.09 and 16. 0 +/- 1.53 fmol/mg protein) > vagina (12.5 +/- 0.73 and 8.2 +/- 0.57 f mol/mg protein) > uterus (8.0 +/- 0.34 and 6.8 +/- 0.56 fmol/mg protei n) > ovary (6.8 +/- 0.36 and 8.0 +/- 1.05 fmol/mg protein) > oviduct ( 2.1 +/- 0.32 and 1.7 +/- 0.05 fmol/mg protein) in control and neonatal ly DES-exposed mice, respectively. Thus, neonatal DES exposure signifi cantly lowered the binding site level only in the vagina, without modi fying the binding affinity (K-d = 5.4 x 10(-9) M in controls vs 4.6 x 10(-9) M in DES exposed mice). Reduction of EGF receptor level in the vagina correlates with ovary-independent persistent proliferation and keratinization of the vagina induced by neonatal DES exposure. EGF rec eptors were immunohistochemically demonstrated in epithelial cells of vagina, uterus, and oviduct and in stromal cells in uterus and oviduct using a polyclonal antibody to human EGF receptor protein.