Study of EPF-Like Substance(s) Detected in Fertilized Bovine Ovum Culture Medium.

Abstract

Abstract. This study was undertaken to confirm whether early pregnancy factor (EPF)-like substance (s) was secreted by fertilized bovine ova. Using the rosette inhibition test, EPF-like substance(s) was detected in the culture media of fertilized bovine ova, while this substance was not found in the culture media of unfertilized bovine ova. EPF-like activity, analyzed by HPLC-gel permeation chromatography, was present between molecular weights of 16 and 37 KD. In conclusion, EPF-like substance(s) is secreted by fertilized bovine ovum and has a molecular weight of 16-37 KD.

Early Pregnancy Factor: EPF-Like Substance(s) Purified from Pregnant Bovine Ovary and in vitro Fertilized Ovum Culture Medium

“…Also, Ikemizu et al [14] indicated that IVF-OCM had EPF positive activity with a molecular weight of 16-37 KD as analyzed by HPLC-gel filtration. Therefore, from these results, we expected that EPF may have two forms.…”

“…Also, Nancarrow et al [25] suggested that a substance "zygotin" was released by the fertilized egg, and this stimulates the production of EPF, most probably from the ovary containing the corpus luteum. Moreover, Ikemizu et al [14], Sueoka [16] and Bose et al [15] reported that EPF was detected in fertilized ovum culture medium. From these reports and our results, we hypothesized about the secretion site and function of EPF.…”

“…In the early 1990s, Cavanagh et al [19] indicated that EPF was secreted from the ovary, Sueoka [16] reported that EPF activity in the culture medium of fertilized human ova increased as ova development progressed, and oviduct or cumulus cells did not participate in EPF secretion. Moreover, EPF has been detected in the culture medium of bovine and human fertilized ova [14,15]. Therefore, it is thought that EPF has two forms (i.e., ovarian origin and fertilized ova origin) during the preimplantation period.…”

EPF as a Marker for Early Embryonic Losses in Repeat Breeders.

“…All samples were evaluated for RIT with the rossete inhibition test described by Ikemizu et al [7]. ALS was prepared as follows: Ox lymphocytes were isolated with a Ficoll gradient.…”

Bovine Early Pregnancy Factor in Recipient Serum with Embryo Transfer on the Day More Than 5 Days Different from the Estrus Cycle of Donor

“…EPF has been also detected in the pregnant sera of humans, cattle and some other species [2,6] and in the culture medium of fertilized ova [7][8][9].…”