Ghrelin negatively affects the function of ovarian follicles in mature pigs by direct action on basal and gonadotropin-stimulated steroidogenesis.

We previously showed that expression of ghrelin messenger RNA is significantly increased in the ovaries of cycling pigs but not in prepubertal animals and that ghrelin stimulates estradiol (E2) secretion by ovarian follicles in prepubertal animals. The present study investigated in vitro the role of ghrelin in regulating the ovarian steroidogenesis during estrus cycle in mature pigs. Small (SFs), medium (MFs), and large (LFs) ovarian follicles were collected on days 4 to 6, 10 to 12, and 16 to 18 of the estrous cycle from cycling pigs and exposed to 20, 100, and 500 pg/mL ghrelin for 24 hours.

In vitro interaction between resistin and peroxisome proliferator-activated receptor γ in porcine ovarian follicles.

In the present study, using real-time polymerase chain reaction and immunoblotting methods, we quantified the expression of peroxisome proliferator-activated receptor (PPAR) γ, PPARα and PPARβ in different sized ovarian follicles (small (SF), medium (MF) and large (LF) follicles) in prepubertal and adult pigs. In prepubertal pigs, PPARγ and PPARα expression was highest in LF; however, PPARβ expression did not differ among SF, MF and LF. In mature pigs, only protein expression of PPARγ and PPARα increased during ovarian follicle development.

Rosiglitazone stimulates peroxisome proliferator-activated receptor gamma expression and directly affects in vitro steroidogenesis in porcine ovarian follicles.

Rosiglitazone is a peroxisome proliferator-activated receptor gamma (PPARγ) synthetic activator from the group of thiazolidinediones often used in the treatment of chronic diseases such as type 2 diabetes and other forms of insulin resistance. The present in vitro study assessed the direct effects of rosiglitazone at 25 and 50 μM doses on PPARγ gene expression, steroid secretion (progesterone [P4], androstenedione [A4], testosterone [T], and estradiol), and protein expression of PPARγ, 3βHSD, CYP17, 17βHSD, CYP19 by porcine ovarian follicles from prepubertal and cycling animals. We analyzed also steroid enzymatic activity by conversion of pregnen-3β-ol-20-one to P4, P4 to A4, and A4 to T.

Cooperation of bisphenol A and leptin in inhibition of caspase-3 expression and activity in OVCAR-3 ovarian cancer cells.

This study was designed to investigate the effect of bisphenol A and leptin on caspase-3 expression and activity in OVCAR-3 ovarian cancer cells. Caspase-3 and survivin expression was measured at the transcript level by real-time PCR and at the protein level by Western blotting. In addition, caspase-3 activity was measured, using a fluorometric assay, upon exposure to bisphenol A (40 nM) alone, leptin (2.

Effects of resistin on porcine ovarian follicle steroidogenesis in prepubertal animals: an in vitro study.

Background: Resistin was first reported to be an adipocyte-specific hormone, but recent studies have indicated a connection between resistin and reproductive function. However, it is not yet known if resistin is expressed by the ovary and if it can affect steroidogenesis in ovarian follicles from prepubertal pigs.

Methods: In this study, using real time PCR, immunoblotting, and ELISA, we quantified resistin expression and concentration in maturing ovarian follicles (small, 3-4 mm; medium, 4-5 mm; large, 6-7 mm) collected from prepubertal pigs.

Supraphysiological leptin levels shift the profile of steroidogenesis in porcine ovarian follicles toward progesterone and testosterone secretion through increased expressions of CYP11A1 and 17b-HSD: a tissue culture approach.

Evidence from both clinical and animal studies suggests that exposure to excess androgens results in cyst formation. The present in vitro study assessed the effects of supraphysiological concentrations of leptin (20 and 40 ng/ml) on progesterone (P(4)), androstenedione androstendione (A(4)), testosterone and estradiol (E(2)) secretion by ELISA and the expression of CYP11A1, CYP17, 17b-hydroxysteroid dehydrogenase (17b-HSD) and CYP19 by western blot to answer the question of whether leptin could be independent risk factor for cystformation in pigs. Small- and medium-sized ovarian follicles were collected from prepubertal and cycling pigs.

Polybrominated diphenylethers (PBDEs) act as apoptotic factors in the corpus luteum in addition to having a short-term stimulatory effect on progesterone secretion by luteal cells.

To the best of our knowledge, there is a lack of data showing effect of polybrominated diphenyl ethers (PBDEs) on the corpus luteum (CL), a mini-endocrine gland responsible for a normal estrous cycle and the maintenance of pregnancy. Luteal cells obtained from corpora lutea (8-10 days after ovulation) were exposed to PBDE 47, 99, and 100 at doses of 50, 250, and 500 ng/ml for 24 and 48 hours. The progesterone (P4) level in the culture medium and caspase-3, -8, and -9 activities in the cells were estimated by ELISA.

Halowax 1051 affects steroidogenesis, 17β-hydroxysteroid dehydrogenase (17β-HSD) and cytochrome P450arom (CYP19) activity, and protein expression in porcine ovarian follicles.

We evaluated the effect of Halowax 1051 on ovarian follicular testosterone (T) and estradiol (E2) secretion determined by EIA and on the expression of 17β-HSD and CYP19 analyzed by Western blot. 17β-HSD and CYP19 activity were determined indirectly by measuring the conversion of androstenedione (A4) to T and T to E2, respectively. Additionally, CYP19 activity by dibenzylfluorescein assay.

Differential accumulation of HCBz and PeCBz in porcine ovarian follicles and their opposing actions on steroid secretion and CYP11, CYP17, 17β-HSD and CYP19 protein expression. A tissue culture approach.

In the current study, we determined in vitro accumulation of hexachlorobenzene (HCBz) and pentachlorobenzene (PeCBz) in porcine ovarian follicles, the effect on steroidogenesis and the expression of enzymes responsible for steroid synthesis. Sixty percent of the HCBz and almost 100% of the PeCBz that was added to the culture medium accumulated in ovarian tissue, and only 1% of each was found in the medium. An inhibitory HCBz effect and stimulatory PeCBz effect on testosterone and estradiol secretion were noted.

Effect of ghrelin on proliferation, apoptosis and secretion of progesterone and hCG in the placental JEG-3 cell line.

To determine the effect of ghrelin on placental cell proliferation, apoptosis and hormone secretion we cultured human JEG-3 cells with 100, 250, 500 or 1000 pg/ml of ghrelin for 48 hours. Ghrelin stimulated cell proliferation and decreased caspase-3 activity. All of the investigated ghrelin concentrations decreased progesterone (P(3)) but had no effect on human chorionic gonadotrophin (hCG) secretion.

Effect of pituitary growth hormone and insulin-like growth factor type-I on proliferation, apoptosis and hormone secretion of the placental cell line JEG-3.

Objective: Placenta human choriocarcinoma JEG-3 cells were used to study the possibility that pituitary growth hormone (GH) and insulin-like growth factor type I (IGF-I) act on first trimester of pregnancy progesterone (P4) and human chorionic gonadotropin (hCG) secretion, cell proliferation and apoptosis.

Material And Methods: The JEG-3 cell line was cultured in Dulbecco modified eagle medium without phenol red containing 10% FBS. The cells were plated in 96-well plates at the density of 3 x 10(3) for 24 h and treated with 10, 50, 100, or 200 ng/ml of GH or 10, 30, 100, or 250 ng/ml of IGF-I for 24 h.