The aim of this study was to determine how luteal cells of the hormone-primed (luteinized) ovary process low density lipoproteins (LDL). Ovary uptake of perfused 125I-LDL was assessed by tissue levels of radioactivity; the distribution of LDL protein in cells was assessed on autoradiograms of the fixed tissue; and the level of stimulation of steroidogenesis, as well as degradation of LDL protei...

In bovine luteal cells, progesterone can directly affect its own synthesis by increasing the activity of 3β-HSD. The effect of progesterone on its own secretion coincides with increased expression of the genes for 3βHSD, StAR, and cytochrome P450scc. Therefore, progesterone regulates its own synthesis by affecting the activity of the enzymes that take part in luteal steroidogenesis, and also by...

This research aimed to investigate the effects of dbcAMP on steroid accumulation by culturing two distinct luteal cell subpopulations isolated from early and late luteal stage corpora lutea. Cells were isolated from corpora lutea collected from eight Angora goats on either the 5th or 15th days of their estrous cycles. Cell isolation was performed by enzymatic digestion using collagenase and DNa...

OBJECTIVE To examine the possible direct effect of human growth hormone (hGH) on basal and human chorionic gonadodotropin (hCG)-stimulated progesterone (P) production by cultured human luteal cells. DESIGN Cultures of human luteal cells from early and midluteal phase. SETTING All corpora lutea were obtained from the Obstetrics and Gynecology Department of the Catholic University, a public c...

OBJECTIVE To examine the possible direct effect of insulin-like growth factor (IGF)-I and IGF-II on basal and hCG-stimulated P production by cultured human luteal cells. The possible role of IGF-I as mediator of GH action on luteal steroidogenesis also was investigated. DESIGN Cultures of human luteal cells from early and midluteal phase. SETTING All corpora lutea were obtained from the Obs...

Effects of hypophysectomy or reduction of the conceptus number on luteal steroidogenesis were studied in the pregnant rat. On day 7 of pregnancy (day 1 = day of insemination), the number of conceptuses was adjusted to one by aspirating all but one conceptus from the uterus. Another group of rats received hypophysectomy on day 12 of pregnancy. On day 15 of pregnancy, the weights of the corpora l...

Oxytocin (OT) may be implicated in the modulation of hypothalamo-pituitary-adrenal axis (HPA) at each level. In mature females the influence of OT on the HPA axis appeared to be dependent on ovarian steroid milieu and stress. In cyclic sows, the role of OT in the regulation of corticoid secretion is unknown. In the present study changes in plasma cortisol and corticosterone concentrations in re...

Epoxyeicosatrienoic acids (EpETrEs), produced from arachidonic acid via cytochrome P450 (CYP) epoxygenases, regulate inflammation, angiogenesis, cellular proliferation, ion transport and steroidogenesis. EpETrE actions are regulated through their metabolism to diols (dihydroxyeicosatrienoic acids; DiHETrE) via the enzyme soluble epoxide hydrolase (EPHX2). We set out to determine, therefore, whe...