Oxytocic polypeptides in human urine.

The work of Gomes on the polypeptide in human urine which causes contraction of the rat uterus has been extended. Concentrates were prepared by means of paper pulp columns similar to those used by Rocha e Silva and his colleagues for the purification of bradykinin, and evidence was obtained for the presence of two different active substances not only in human urine but also in a preparation of bradykinin. The effect of human urine on the rat uterus is probably due to bradykinin itself or a mixture of similar substances.