Endocrine delivery of interferon tau protects the corpus luteum from prostaglandin F2 alpha-induced luteolysis in ewes.

Paracrine release of ovine interferon tau (oIFNT) from the conceptus alters release of endometrial prostaglandin F2 alpha (PGF) and prevents luteolysis. Endocrine release of oIFNT into the uterine vein occurs by Day 15 of pregnancy and may impart resistance of the corpus luteum (CL) to PGF. It was hypothesized that infusion of recombinant oIFNT (roIFNT) into the uterine or jugular veins on Day 10 of the estrous cycle would protect the CL against exogenous PGF-induced luteolysis.

Temporal gene expression in equine corpora lutea based on serial biopsies in vivo.

A biopsy procedure was developed to enable repeated sampling of a single equine corpus luteum (CL) over the course of an estrous cycle. The tissue collected was utilized in characterizing mRNA abundance for genes involved in luteal formation, function, and regression in the cyclic mare. Serial biopsies of CL in cyclic mares (2.

Uterine vein infusion of interferon tau (IFNT) extends luteal life span in ewes.

Interferon tau (IFNT) from the ovine conceptus has paracrine actions on the endometrium that alter release of prostaglandin F(2alpha) (PGF) and protect the corpus luteum (CL). Antiviral activity in uterine vein blood and expression of interferon-stimulated genes (ISGs) in CL is greater in pregnant than in nonpregnant ewes. We hypothesized that IFNT contributes to antiviral activity in uterine vein blood and has endocrine actions on the CL.

Progesterone inhibits oxytocin- and prostaglandin F2alpha-stimulated increases in intracellular calcium concentrations in small and large ovine luteal cells.

There is increasing evidence that the corpus luteum has an important role in regulating its own demise. A series of experiments was performed to study the effects of luteal concentrations of progesterone on the functions of steroidogenic luteal cells. In the first experiment, steroidogenic small luteal cells (SLCs) were separated from endothelial cells, and it was determined that it was the SLCs that contained receptors for oxytocin.

Judge, jury and executioner: the auto-regulation of luteal function.

Experiments were conducted to further our understanding of the cellular and molecular mechanisms that regulate luteal function in ewes. Inhibition of protein kinase A (PKA) reduced (P < 0.05) secretion of progesterone from both small and large steroidogenic luteal cells.