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Granulosa Layer (granulosa + layer)

Distribution by Scientific Domains

Life Sciences	50%

Selected Abstracts

Influence of oocyte collection technique on initial chromatin configuration, meiotic competence, and male pronucleus formation after intracytoplasmic sperm injection (ICSI) of equine oocytes,

MOLECULAR REPRODUCTION & DEVELOPMENT, Issue 1 2001
Maria Elena Dell'Aquila
Abstract There is a great variability in the success of horse oocyte maturation and fertilization among laboratories. This study was conducted to determine if the meiotic and developmental competence of horse oocytes could be dependent on the method of oocyte collection, i.e., aspiration of follicular fluid with a vacuum apparatus, or opening follicles and scraping the granulosa layer. Horse oocytes were recovered from abattoir ovaries by aspiration or scraping and classified as having compact (Cp), expanded (Ex), or partial (P) cumuli. In Experiment 1 (Part A in May and Part B in October), oocytes were fixed immediately after collection to assess whether the collection method influenced the initial chromatin configuration of oocytes. In Experiment 2, in vitro maturation rates of oocytes recovered by aspiration or scraping were compared. In Experiment 3, oocytes were matured in vitro and submitted to intracytoplasmic sperm injection (ICSI). Initial chromatin configuration differed according to collection method in that there was a significantly higher prevalence of diffuse chromatin within the germinal vesicle in oocytes recovered by scraping than in oocytes recovered by aspiration (29/87, 33% and 28/166, 17%, respectively; P,<,0.01). Maturation of oocytes to metaphase II did not significantly differ between scraped and aspirated oocytes (56/101, 55.4 % vs. 65/106, 61.4%, respectively). The overall pronucleus formation rate after ICSI of oocytes recovered by scraping was not significantly different than that of oocytes recovered by aspiration (50/99, 52.6% vs. 50/85, 68.5 %, respectively); however, the rate of abnormal fertilization was significantly higher for oocytes collected by aspiration (14/73, 19% vs. 6/94, 6%, respectively; P,<0.05). These results demonstrate that the collection method affects the population of recovered oocytes and may contribute to differences in results observed among laboratories working with horse oocytes. Mol. Reprod. Dev. 60: 79,88, 2001. © 2001 Wiley-Liss, Inc. [source]

Heat Shock Protein 70 and Sex Steroid Receptors in the Follicular Structures of Induced Ovarian Cysts

REPRODUCTION IN DOMESTIC ANIMALS, Issue 5 2009
NR Salvetti
Contents The purpose of this study was to estimate the expression and relative amounts of estrogen (ER) and progesterone receptors (PR) and their isoforms as well as heat shock protein 70 (HSP70) in ovaries of rats with induced cystic ovarian disease (COD). Primary, secondary, tertiary, atretic and cystic follicles were evaluated by immunohistochemistry and total ovarian proteins were analyzed by Western blot. In the granulosa layer, growing and cystic follicles in the treated group have a higher expression of ER, than growing follicles of control individuals. In the theca interna layer, tertiary follicles presented a significantly higher expression of ER, in the treated group. An increase in total ER, protein was detected in the treated group. Granulosa cells of all growing, atretic and cystic follicles show a lower expression of ER, in animals with COD, and the total protein expression of ER, was lower in this group. The expression of PR was lower in the granulosa cell layer of tertiary and cystic follicles in treated animals, and theca interna layer had less intense immunostaining in this group. Although there were no differences in the expression of PR-B by Western blotting, the expression of PR-A was higher and the expression of PR-C was smaller in the treated group. An intense HSP70 immunostaining was observed in the cells of cystic follicles. By Western blotting, higher protein expression of HSP70 was detected in the ovarian samples of the control group than those of the treated ones. Ovaries of animals with COD exhibited an altered steroid receptor expression and subtype balance as compared with control animals, and an increase in HSP70 immunoexpression. [source]

Angiogenesis in Developing Follicle and Corpus Luteum

REPRODUCTION IN DOMESTIC ANIMALS, Issue 4 2004
C Tamanini
Contents Angiogenesis is a process of vascular growth that is mainly limited to the reproductive system in healthy adult animals. The development of new blood vessels in the ovary is essential to guarantee the necessary supply of nutrients and hormones to promote follicular growth and corpus luteum formation. In developing follicles, the pre-existing endothelial cells that form the vascular network in the theca layer markedly develop in response to the stimulus of several growth factors, mainly produced by granulosa cells, such as vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF). The angiogenic factors also promote vessel permeability, thus favouring the antrum formation and the events inducing follicle rupture. After ovulation, newly formed blood vessels cross the basement membrane between theca and granulosa layers and continue a rapid growth to sustain corpus luteum development and function. The length of luteal vascular growth varies in cycling and pregnant animals and among species; both angiogenesis and subsequent angioregression are finely regulated by systemic and local factors. The control of angiogenic development in the ovary could be a useful tool to improve animal reproductive performances. [source]

Intraovarian Localization of Growth Factors in Induced Cystic Ovaries in Rats

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 2 2007
H. H. Ortega
Summary We hypothesized that the special hormonal environment present in animals with cystic ovarian disease (COD) interferes with cellular production of growth factors (GFs). The objective of the present study was to characterize the expression of insulin-like growth factor (IGF)-I, fibroblast growth factor (FGF)-2 and vascular endothelial growth factor (VEGF) in induced COD using immunohistochemistry. We used an experimental model based on the exposure to constant light of adult rats during 15 weeks. We quantified the expression of GFs in cystic and normal ovaries by the Immunohistochemical Stained Area (IHCSA). In animals with COD, a significant reduction in the IHCSA of IGF-I in the follicular fluid, theca and granulosa layers of cysts occurred; and an increase in the interstitial tissue with regard to the control group. We found moderate immunoreactivity of FGF-2 in granulosa and theca layers of secondary and tertiary follicles and lower expression in the granulosa and theca interna layers of cystic follicles. Immunoexpression of VEGF was found in granulosa and theca cells of secondary and tertiary follicles. This study shows changes in the ovarian expression of IGF-I, FGF-2 and VEGF in induced COD. We can propose that an alteration in the control of the follicular dynamic, through the GFs, added to other features, could be involved in the ovarian cyst pathogenesis. [source]