Identification of somatostatin in the human placenta.

High pressure liquid chromatography (HPLC), gel chromatography and radioimmunoassay (RIA) were applied to the identification of cyclic somatostatin in human placental tissue. Methanol extracts of the placenta were treated with acetic acid and chloroform, purified on an octadecylsilane column, fractionated on HPLC and gel filtration, and assessed by RIA. It is concluded that human placental somatostatin is similar or identical to cyclic somatostatin on other tissue.