The oxytocic principle of the posterior lobe of the pituitary gland. I

Abstract

Norite charcoal adsorbed the oxytocic principle from an extract of the posterior lobe. The adsorption was continuous between pH 1 and 13 and the active substance may be eluted by glacial acetic acid. In case of a purified extract, there was about an average of 80% recovery. It fell to a minimum of 55 to 60% at pH 5.7 but at pH 2 and pH 11 rose to about 100%. With fresh partially purified extracts, about 50% of the total solids were not adsorbed at pH 3.8, and 40% at pH 13. The weight of solids not adsorbed fell between these limits and was about 0 at pH 7. In case of mature extracts, about 50% of the solids were adsorbed between pH 1 and 13 and the value was about 64% at pH 11. The most active preparation contained 225 international oxytocic units per mgm.