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

Ito, Kazuei; Ikemizu, Yoshimi; Takahashi, Jutaro; Yasuda, Yasuhisa; Kawahata, Kyoko; Goto, Taichi

doi:10.1262/jrd.41.85

Cited by 6 publications

(5 citation statements)

References 19 publications

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“…Several authors have reported purification of EPF of different molecular size, 49 , 50 , 51 , 52 , 53 identified by activity in the rosette inhibition test (see following). The dose–response curve of EPF in this assay is bell shaped with high as well as low concentrations giving negative results; as the concentration of EPF decreases, the curve moves to the left.…”

Section: Nature Of the Early Pregnancy Factor Molecule And Factors Afmentioning

confidence: 99%

Early pregnancy factor: An extracellular chaperonin 10 homologue

Morton

1998

Immunol Cell Biol

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Summary Early pregnancy factor (EPF) has been identi®ed as a homologue of chaperonin 10 (cpn10) with immunosuppressive and growth factor properties. As a homologue of cpn10, it belongs to the heat shock family of proteins (hsp) but, unlike other members of this family, EPF is detected extracellularly. Early pregnancy factor was ®rst discovered in pregnancy serum by the rosette inhibition test, and the novelty of its discovery was that its presence could diagnose pregnancy within 6±24 h of a fertile mating. As well as being a monitor of the presence of a viable embryo, it is necessary for embryonic survival. In this capacity it acts as both an immunosuppressant and growth factor. Early pregnancy factor is also a product of proliferating primary and neoplastic cells and functions as an autocrine growth factor both in vivo and in vitro. It has a modifying e ect on the outcome of experimental autoimmune encephalomyelitis, an animal model of multiple sclerosis. Early pregnancy factor is considered to be one of the major factors involved in the modi®cation of multiple sclerosis observed during pregnancy.

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Section: Nature Of the Early Pregnancy Factor Molecule And Factors Afmentioning

confidence: 99%

Early pregnancy factor: An extracellular chaperonin 10 homologue

Morton

1998

Immunol Cell Biol

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“…There have been remarkable discrepancies among molecular weights of purified EPF reported by different investigators (ranging from 10 to 21.5 kD), probably due to differences in original materials and isolation procedures. 9,24,38,39 Ito et al 13 insisted that, because Cavanagh and Morton purified EPF from human platelets, it might not be a true EPF. In order to identify true EPF, EPF has to be purified from early-pregnant serum.…”

Section: Discussionmentioning

confidence: 99%

Chaperonin 10 in the Rat Oocytes and Early Embryos: its Expression and Activity for Early Pregnancy Factor

Kawamura

Fukuda²,

Itoh³

et al. 2000

American J Rep Immunol

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“…Nancarrow et al [15] suggested that EPF production is stimulated by zygotin released from fertilized ova and the most probable production sites are ovaries. Ito et al [21] proposed a hypothesis concerning the ovarian EPF secretion in cattle as follows: Preimplantation-embryo-origin EPF is likely secreted immediately after fertilization in the oviduct, and it may modulate the effects of maternal immune cells. Then PAF secreted from the oviduct after the release of preimplantation-embryo-origin EPF induces the ovary to release ovarian-origin-EPF that may provide an immunotolerant environment in the uterus through the blood flow.…”

Section: Discussionmentioning

confidence: 99%

Detection of Early Pregnancy Factor in the Sera of Cows Whose Uteri were Infused with Trophoblastic Cell Culture Medium.

Kawahata¹,

Goto²

1998

Journal of Reproduction and Development

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Abstract. The aim of this study was to examine whether or not uterine infusion with a medium showing positive early pregnancy factor (EPF) activity influences maternal physiology in cattle. Trophoblastic cells derived from 12-day-old bovine embryos were cultured in Dulbecco's PBS (+) at 39 C in air for 24 h. EPF activity was assayed using the rosette inhibition test. A rosette inhibition titer (RIT) above 4 was regarded as indicating positive EPF activity. The trophoblastic cell culture medium (Tro-CM) showed positive EPF activity. On days 7 to 12 after estrus, five cows each received a nonsurgical infusion of Tro-CM (0.25 ml) in the lumen of the uterine horn. Blood samples were collected daily by the tail artery or vein puncture from day 0 (the day of infusion) to day 5. All five cows showed positive EPF activity in their sera on days 2 to 4, and three cows out of the five kept showing positive EPF activity for 2 to 3 days. The result demonstrated that sera of cows infused with a small amount of EPF-positive medium (Tro-CM) into the uterus showed temporary positive EPF activity in maternal serum, further suggesting that EPF released from Tro-CM would induce a release of maternal EPF, but not by directly entering into the maternal blood flow.

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

Cited by 6 publications

References 19 publications

Early pregnancy factor: An extracellular chaperonin 10 homologue

Early pregnancy factor: An extracellular chaperonin 10 homologue

Chaperonin 10 in the Rat Oocytes and Early Embryos: its Expression and Activity for Early Pregnancy Factor

Detection of Early Pregnancy Factor in the Sera of Cows Whose Uteri were Infused with Trophoblastic Cell Culture Medium.

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