Contractions of the isolated uterus stimulated by epidermal growth factor

Epidermal growth factor (EGF) produces uterine contractions in tissues removed from immature and adult rats. EGF produces both an increase in resting tone and the development of rhythmic contractions, and this effect is abolished by treatment with antibodies against EGF. The ED50 for this response is observed at an EGF concentration of 3.5 nM. This in vitro effect of EGF requires treatment of the animals in vivo with estradiol for 24 h before removal of uterine tissue. This effect of estradiol does not appear to be due solely to an induction of tissue EGF receptors. These results demonstrate a new activity of EGF and suggest a previously unrecognized function for this peptide growth factor.