Background: Zucker fatty (fa/fa) rats are a well-understood model of obesity and hyperinsulinemia. It is now thought that obesity/hyperinsulinemia is an important cause of endocrinological abnormality, but to date there have been no reports on the changes in ovarian morphology or the ovarian androgen profile in rat models of obesity and insulin resistance.
Methods: In this study we investigated the effects of obesity and hyperinsulinemia on ovarian morphology and the hormone profile in insulin-resistant Zucker fatty rats (5, 8, 12 and 16 weeks of age, n = 6-7).
Polycystic ovary syndrome (PCOS) is a heterogeneous group of disorders that occur fairly commonly in women of reproductive age and are characterized by a variety of clinical manifestations, including insulin resistance that is independent of obesity. Recent studies suggest that altered adipocytokine gene expression is closely associated with insulin resistance and that single nucleotide polymorphisms (SNPs) modulate the expression and/or function of these genes, thereby affecting insulin sensitivity. With that in mind, we investigated whether SNPs at position -420 of the resistin gene (RETN) and/or -11377 of the adiponectin gene (ADIPOQ) modulate the susceptibility to PCOS.
View Article and Find Full Text PDFRecent studies indicate that insulin resistance resulting from altered post-receptor signaling is associated with polycystic ovary syndrome (PCOS). We hypothesized that insulin receptor substrate-1 (IRS-1) Gly972Arg polymorphism and/or ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) Lys121Gln polymorphism predisposes women to PCOS and that these polymorphisms also affect anthropometric variables, glucose metabolism and androgen synthesis. To test those ideas, we studied the genotypes, indexes of insulin resistance, and hormone profiles in 123 Japanese women with PCOS and 380 healthy Japanese controls.
View Article and Find Full Text PDFMatrix metalloproteinases (MMP) are capable of degrading a variety of extracellular matrix (ECM) proteins and are also involved in the processing of a number of bioactive molecules. Our findings indicate that the functions of MMP in the ovary and uterus are organ-specific and time-dependently vary during the reproductive cycle. Prolactin induces structural luteolysis indicated by loss of luteal weight, protein and DNA within 36 h after pretreatment with ergot alkaloid.
View Article and Find Full Text PDFOne of the characteristics of polycystic ovary syndrome (PCOS) is the presence of cystic follicles in various stages of growth and atresia, the latter of which is known to be the result of apoptosis and tissue remodeling. To further investigate the process of follicular atresia, we compared ovarian expression and localization of Fas, Fas ligand (FasL), casapse-8 and membrane-type1 matrix metalloproteinase (MT1-MMP) in rats treated with dehydroepiandrosterone (DHEA) as a model of PCOS, and in control rats. We found that the numbers of TdT-mediated dUTP-biotin nick end-labeling (TUNEL)-positive follicles were significantly higher in ovaries from PCOS rats than in those from control rats (P < 0.
View Article and Find Full Text PDFBackground: The changes occurring in the rodent uterus after parturition can be used as a model of extensive tissue remodeling. As the uterus returns to its prepregnancy state, the involuting uterus undergoes a rapid reduction in size primarily due to the degradation of the extracellular matrix, particularly collagen. Membrane type-I matrix metalloproteinase (MT1-MMP) is one of the major proteinases that degrades collagen and is the most abundant MMP form in the uterus.
View Article and Find Full Text PDFWe investigated the mechanism by which a GnRH agonist (GnRHa) affects ovarian vascularity, vascular permeability, and expression of the tight junction protein claudin-5 in a rat model of ovarian hyperstimulation syndrome (OHSS). Hyperstimulated rats received excessive doses of pregnant mare serum gonadotropin (PMSG; 50 IU/d) for 4 consecutive days, from d 25 to 28 of life, followed by 25 IU human chorionic gonadotropin (hCG) on d 29. Control rats received 10 IU PMSG on d 27 of life, followed by 10 IU hCG on d 29.
View Article and Find Full Text PDFIntrauterine growth restriction (IUGR) has a multifactorial pathogenesis and is an important cause of perinatal mortality. The relationship between fetal weight and placental blood flow in an animal model of IUGR has been investigated, showing that fetal growth is regulated by placental blood flow. The aim of the present study was to determine whether ischemia-reperfusion (I/R) injury stimulates the prostaglandin E2 (PGE2) system or the vascular endothelial growth factor (VEGF) system in the placenta of a rat IUGR model.
View Article and Find Full Text PDFStructural luteolysis induced by gonadotropin releasing hormone agonist (GnRHa) or prolactin (PRL) is defined as histological involution of the corpus luteum. We reported that one of the mechanisms of structural luteolysis induced by PRL was tissue remodeling by matrix metalloproteinase (MMP) and also apoptosis in superovulated rats. We also reported that GnRHa induced structural luteolysis with elevation of MMP.
View Article and Find Full Text PDFObjective: Using hyperstimulated rats, to elucidate the mechanisms of gonadotropin-releasing hormone agonist (GnRH-a) treatment to prevent early ovarian hyperstimulation syndrome (OHSS).
Design: Descriptive study of hyperstimulated rats as an early OHSS model with Western blot analysis, Northern blot hybridization, and vascular permeability assay.
Setting: Experimental laboratory research.
The expression of membrane type 1 (MT1) matrix metalloproteinase (MMP), MMP-2, and tissue inhibitors of MMP-1 and -2 during structural involution of the human corpus luteum was examined using immunohistochemistry, Northern blotting, Western blotting, gelatin zymography and in-situ hybridization techniques. The corpora lutea of 20 patients were investigated at the time of total hysterectomy and were obtained from five patients each in the early, mid- and late luteal phases and during gestation. Immunohistochemistry for MT1-MMP in corpus luteum showed that the protein appeared in granulosa lutein cells in the late luteal phase.
View Article and Find Full Text PDFWe experienced a case of hemorrhagic infarction of the ovarian fibroma and that indicated the characteristic following appearance: exhibiting a high signal intensity area observed at the periphery of mass on T1-weighted MRI (magnetic resonance imaging). It was thought that this appearance developed because hemorrhagic infarction was caused by subacute ovarian torsion. This is a useful finding for suspecting hemorrhagic infarction preoperatively.
View Article and Find Full Text PDFObjectives: The aim of our study was to evaluate the anti-invasive effect of MMI-166, a new matrix metalloproteinase (MMP) inhibitor in cervical carcinoma cell lines.
Methods: We analyzed the invasive activities of cervical carcinoma cell lines (CAC-1, CaSki, and SiHa) and the gene expression of various matrix proteinases (matrix metalloproteinase-1 [MMP-1], MMP-2, MMP-9, membrane-type MMP type 1 [MT1-MMP], MT2-MMP, and MT3-MMP) and their inhibitors (tissue inhibitor of metalloproteinase type 1 [TIMP-1] and TIMP-2). The effect of MMI-166 was analyzed by in vitro invasion assay.
Objective: To evaluate the expression of mRNA of vascular endothelial growth factor (VEGF), its receptors Flt-1 and KDR/Flk-1, and Ets-1 in human corpora lutea.
Design: Prospective laboratory study.
Setting: University hospital in Japan.
Polycystic ovary syndrome (PCOS) is characterized by cystogenesis; however, the cause of this cystogenesis is unknown. At ovulation, preovulatory collagenolytic activities in the ovarian follicles increase and various proteinases are needed to degrade the tissues surrounding the follicles. To clarify the roles of enzymes in collagen degradation of the follicular wall of polycystic ovary (PCO) in relation to the cystogenesis, we examined expression of lysyl oxidase (LOX), which initiates cross-link formation of the collagen and elastin in the extracellular matrix, and expression of matrix metalloproteinases (MMPs) in ovaries of model rats with PCO induced by dehydroepiandrosterone (DHEA) compared with MMP expression in control rats.
View Article and Find Full Text PDFObjectives: The aim of our study was to determine the important molecules responsible for the invasive activity of ovarian cancer cells.
Methods: We compared the biological characteristics, that is, growth rate, motility, and invasive activity, of five ovarian cancer cell lines with the gene expression of various matrix proteases (matrix metalloproteinase-1 [MMP-1], MMP-2, MMP-9, membrane-type MMP type 1 [MT1-MMP], MT2-MMP, MT3-MMP, urokinase plasminogen activator [uPA]), their inhibitors (tissue inhibitor of metalloproteinase type 1 [TIMP-1], TIMP-2, plasminogen activator inhibitor type 1, [PAI-1], and PAI-2), and the potential transcriptional regulators E1AF and Ets-1.
Results: There was no clear correlation in the growth rate, motility, and invasion, suggesting that there are independent properties for malignant potential in ovarian cancer cells.
Background: Molar pregnancy with a coexisting live fetus is a rare occurrence. We report the only known case with a surviving coexistent fetus after gamete intrafallopian transfer (GIFT).
Case: After GIFT, a 28-year-old primary infertility patient was diagnosed as having a complete hydatidiform mole coexisting with a live fetus at 13 weeks of gestation.
In general, growth hormone acts as a factor promoting cell proliferation in the positive direction and suppresses apoptosis. No report has described growth hormone (GH)-induced structural luteolysis. The present studies showed that GH induced structural luteolysis in rats after the induction of functional luteolysis by treatment with bromocriptine, and that apoptotic cells were present among luteal cells during structural luteolysis as shown by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling.
View Article and Find Full Text PDFGonadotropin-releasing hormone (GnRH) and its agonist analog (GnRHa) are well known to have luteolytic effects. We previously reported that prolactin (PRL) stimulated matrix metalloproteinase (MMP)-2 activity to degrade collagen type IV as a mechanism of structural luteolysis. The effects of GnRHa treatment on developed corpora lutea are unknown.
View Article and Find Full Text PDFGynecol Endocrinol
February 1998
The human corpus luteum produces both estradiol and progesterone. It is well known that there are both autocrine and paracrine systems for the regulation of the corpus luteum and that estradiol regulates the progesterone production of the corpora lutea of some other species. To assess the direct effects of estrogen on human luteal function, we performed cell culture experiments.
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