Acidic acetone extract from pregnant sow ovaries is a rich source of substances affecting uterine contractility in vitro.

Acidic acetone extract of pregnant sow ovaries was subjected to Sephadex G-25 chromatography. The solution coming from column was analysed for UV absorption, molecular weight, and also for its biological effect on a myometrium strip in vitro. This biodetection system has made it possible continuously to determine the biologically active fractions eluted from the Sephadex G-25 column. The reference materials to calibrate the Sephadex G-25 column were Blue dextran and acetone, while for calibration of the biodetection system, synthetic oxytocin was used. The extract of ovaries of pregnant sows was separated chromatographically into 8 different, biologically active fractions with distinct UV absorption and molecular weight. One of these fractions showed elution characteristics and biological effect similar to those of synthetic oxytocin in the same biodetection system. The results indicated that acidic acetone extract originating from ovaries of pregnant sows is a rich source of biologically active substances with effects on the myometrium strips in pregnancy. Partial identification of oxytocin-like substances in the ovarian extract verified the effectiveness of the biodetection system in the first steps of research to obtain new, biologically active substances from different unpurified extracts.