Partial purification of the ovarian oviposition-inducing factor and estimation of its chemical nature.

The ovarian ruptured follicles larger than 0.2 g. of wet weight were collected from laying hens and an ovarian oviposition-inducing factor (OOIF) was extracted from the follicles. The extract was chromatographed on a column of Sephadex G-75. Material from the active region for inducing premature oviposition was subjected to thioglycollate or trypsin treatment. It was found that oxytocic activity of this material was completely destroyed by thioglycollate buy not by trypsin, when tested on the contractility of the isolated hen's uterus. The OOIF was found to be diffusible through a cellophane bag. It is suggested that the OOIF may be a relatively small molecule have a disulfied bridge and it seems to be a hormone or hormone-like substance resembling the posterior pituitary hormones in the chemical nature.