A UTERINE MUSCLE CONTRACTILE SUBSTANCE OBTAINED FROM A HUMAN PLACENTAL CDNA LIBRARY

A cDNA clone coding for an oxytocin-like substance was prepared from a human placental cDNA library. using oxytocin antiserum. The cDNA size was approximately 900 bp. A mammalian expression vector containing th e cDNA was constructed and transfected into Chinese hamster ovary (CHO ) cells. The expression of immunoreactivity to oxytocin antiserum was observed by radioimmunoassay. The cultured medium of the transfected c ells was assayed for uterine muscle contractile bioactivity using a Ma gnus apparatus. Bioactivity was eliminated by incubation with oxytocin antiserum. Thus, the cDNA done, screened with oxytocin antibody, is s urmised to code for an oxytocin-like activity, but the nucleotide and amino acid sequences responsible for the biological activity remain to be clarified.