scholarly journals Plasma LH and Progesterone Levels before and after Ovulation and Observation of Ovarian Follicles by Ultrasonographic Diagnosis System in Dogs.

2000 ◽  
Vol 62 (3) ◽  
pp. 243-248 ◽  
Author(s):  
Masayoshi HASE ◽  
Tatsuya HORI ◽  
Eiichi KAWAKAMI ◽  
Toshihiko TSUTSUI
Keyword(s):  
Ovarian Follicles ◽  
Diagnosis System ◽  
Ultrasonographic Diagnosis ◽  
Before And After

STEROID PRODUCTION BY ISOLATED RABBIT OVARIAN FOLLICLES: EFFECTS OF LUTEINIZING HORMONE FROM MATING TO IMPLANTATION

1977 ◽  
Vol 73 (1) ◽  
pp. 59-65 ◽  
Author(s):  
E. V. YOUNGLAI
Keyword(s):  
Luteinizing Hormone ◽  
Ovarian Follicles ◽  
Steroid Production ◽  
Before And After ◽  
Endocrine Status

SUMMARY Follicles were isolated from rabbits before and after mating and the effects of LH on steroidogenesis were studied using an incubation technique. Before mating testosterone was the major steroid produced in response to LH. Mating or administration of ovine LH in vivo caused the follicles to produce mainly progesterone and these follicles were refractory to LH in vitro. Up to 72 h after mating, LH would stimulate follicles to produce progesterone. At 96 h after mating, the testosterone response to LH was again manifest. These results suggest that the responsiveness of rabbit follicles to LH is dependent on the endocrine status of the animal when the ovaries were removed.

PRE-OVULATORY CHANGES IN RAT FOLLICULAR CYCLIC AMP AND SENSITIVITY TO GONADOTROPHINS

1977 ◽  
Vol 86 (2) ◽  
pp. 384-393 ◽  
Author(s):  
L. Nilsson ◽  
T. Hillensjö ◽  
C. Ekholm
Keyword(s):  
Cyclic Amp ◽  
Present Model ◽  
Lactic Acid Production ◽  
Ovarian Follicles ◽  
Progesterone Synthesis ◽  
Before And After ◽  
Refractory State ◽  
Camp System ◽  
High Concentrations ◽  
Ovulatory Follicles

ABSTRACT Stimulation of ovarian follicles by high concentrations of gonadotrophins has been reported to induce a refractory state in the follicles to further stimulation by the same agent. The present study was undertaken to determine whether a physiological gonadotrophic stimulus would induce a similar desensitization. The levels of cyclic AMP (cAMP) were measured in rat pre-ovulatory follicles before and after the estimated period of gonadotrophin release. The PMSG injected pre-pubertal rat was used as a model of spontaneous ovulation as previously described. Follicles were explanted before and after the period of gonadotrophin release on the day before ovulation (day 30 in the present model) and cAMP was measured either directly or after 1–2 h of incubation. The follicles explanted in the evening of day 30 showed higher levels of cAMP than those isolated in the same morning irrespective of their being incubated or not. Follicular lactic acid production and progesterone synthesis as measured in the incubation medium showed the same pattern. The increase in all three parameters in "evening follicles" could be prevented by giving the animals pentobarbitone before the estimated gonadotrophin release. When the follicles were extirpated in the evening of day 30 and incubated in the presence of LH or FSH, significantly higher concentrations of the two hormones were needed to elicit a further increase in cAMP as compared to follicles isolated in the morning of the same day or from rats treated with pentobarbitone. It is concluded that the pre-ovulatory surge of gonadotrophins induces a desensitization of the cAMP system of rat ovarian follicles toward further action by LH or FSH. This refractory state, however, is not complete but relative under physiological conditions. In the rat, the duration of this phenomenon seems to coincide with the slight but significant elevation of follicular cAMP and to last from a few hours after the gonadotrophin surge up to ovulation. Possible mechanisms of this effect as well as its purpose are discussed.

scholarly journals Application of Omni-ATAC to Profile Chromatin Accessibility Before and After Ovarian Tissue Cryopreservation

2021 ◽  
Author(s):  
Jennifer A. Shannon ◽  
Aishwarya Sundaresan ◽  
Orhan Bukulmez ◽  
Zexu Jiao ◽  
Sarah Capelouto ◽  
...  
Keyword(s):  
Epithelial Mesenchymal Transition ◽  
Ovarian Tissue ◽  
Regulatory Elements ◽  
Ovarian Follicles ◽  
Chromatin Accessibility ◽  
Ovarian Tissue Cryopreservation ◽  
Post Transplantation ◽  
Mesenchymal Transition ◽  
Before And After ◽  
Tissue Cryopreservation

AbstractOvarian tissue cryopreservation and subsequent autologous transplantation has allowed resumption of endocrine function as well as fertility in certain populations. However, graft function is short-lived due to ischemia and aberrant follicular activation post-transplantation. While many studies have focused on gene expression, we wanted to determine whether cryopreservation itself had a deleterious effect on regulatory elements that might influence transcriptional integrity and graft performance. In this study, we used Omni-ATAC to assess genome-wide chromatin accessibility in primary human follicles before and after cryopreservation. Omni-ATAC from fresh ovarian follicles identified active regulatory elements expected to be functional in oocytes and granulosa cells, and gene ontology was consistent with RNA translation/processing and DNA repair. While promoter accessibility was largely maintained in cryopreserved ovarian follicles, we observed a widespread increase in the number of accessible enhancers. Transcription factor motif analysis and gene ontology suggested that this dysregulation was focused around the epithelial-mesenchymal transition. Indeed, transcription factor binding was noted in major pathways involved in this transition: TGF-β and Wnt signaling. Overall, our work provides the first genomic analysis of active regulatory elements in matched fresh and cryopreserved ovarian follicles as they undergo the process of ovarian tissue cryopreservation. Our data suggest that the process of cryopreservation activates an epithelial-mesenchymal transition state, which may lead to graft burn-out post-transplantation. Optimizing this technique in relation to this transition may therefore be an important step towards improving graft longevity and patient outcomes in fertility preservation.Summary sentenceCryopreservation of ovarian cortical tissue results in activation of differentiation and EMT pathways in follicles, which may explain graft burnout after autotransplantation.

scholarly journals Effect of Acute Exposure of Cigarette Smoke on Endometrium Thickness and Number of Ovarian Follicles in Rats

2021 ◽  
Vol 2 (1) ◽  
pp. 1-8
Author(s):  
Izdihar Ramadhanty Abiyasa Putri ◽  
R Haryanto Aswin ◽  
Tri Hartini Yuliawati
Keyword(s):  
Cigarette Smoke ◽  
Negative Impact ◽  
Endometrial Thickness ◽  
Ovarian Follicles ◽  
Reproductive Organ ◽  
Vaginal Swab ◽  
Female Rats ◽  
Acute Exposure ◽  
Before And After ◽  
Histological Slide

Background: Cigarrete smoke has been ascociated with many health-related problems especially in long time use. One of many health problems that are affected is the reproductive system that give negative impact in fertility. However, there are limited studies about this in acute exposure of cigarette smoke. Objective: The aim of this study is to investigate the effect of acute exposure of cigarette smoke on endometrial thickness and number of ovarian follicles in rats. Methods: Thirty adult female rats were randomly divided into 3 groups: P0, P1 and P2. The P1 and P2 groups were exposed to cigarette smoke for 15 days with dose of 2 and 4 cigarettes daily, respectively. Vaginal swab was done twice, before and after the last treatment, to determine the proestrus phase of the animals. Histological slide of uterus and ovarium using Haematoxylin Eosin staining were observed under light microscop. Number of ovarian follicles were measured, and the thickness of endometrium was meassured using CellSens software version 2.3 (Olympus Life Science). Statistical analysis of data was performed using MANOVA in SPSS software version 23 for Windows.   Results: There were no significant differences in both endometrial thickness and number of ovarian follicles between 3 groups (p>0.05). However, we found that there were a downward trend of some variables (endometrial thickness, number of primary follicles, de Graff follicles, and corpus luteum) from P0 to P2. Conclusion: We concluded that acute exposure of cigarette smoke not yet influenced the female reproductive organ, based on histological appearance of endemotrium and ovarium.

scholarly journals miR-199-3p Suppresses Cellular Migration and Viability and Promotes Progesterone Production in Goose Ovarian Follicles Before Selection by Targeting ITGB8 and Regulating Other ECM-related Genes

2021 ◽  
Author(s):  
Qin Li ◽  
Keshan Zhang ◽  
Xianzhi Zhao ◽  
Jing Li ◽  
Youhui Xie ◽  
...  
Keyword(s):  
Cell Migration ◽  
Follicular Development ◽  
Ovarian Follicles ◽  
Cellular Migration ◽  
Differentially Expressed ◽  
Migration And Invasion ◽  
Primary Role ◽  
Progesterone Production ◽  
Before And After ◽  
Follicular Selection

ABSTRACTThe extracellular matrix (ECM) constitutes the follicular basal lamina and is also present between follicular cells. Remodeling of the ECM is believed to be a key event in follicular development, especially follicular selection, and plays important roles in cell migration, survival, and steroidogenesis. miR-199-3p is differentially expressed in the goose follicular granulosa layer during follicular selection and is reported to play a primary role in inhibiting cell migration and invasion. Nevertheless, the effect of miR-199-3p on ovarian follicles and its role in follicular cellular migration are not understood. In this study, we demonstrated by qRT-PCR that miR-199-3p was differentially expressed in the granulosa layer from goose ovarian follicles before and after follicular selection. Additionally, we found that miR-199-3p overexpression could significantly suppress cell viability and migration, as well as elevate both the concentration of progesterone and the expression of key progesterone production genes in cultured granulosa cells (GCs) from goose pre-hierarchical follicles. Furthermore, using dual-fluorescence reporter experiments on 293T cells, we confirmed that miR-199-3p downregulated the expression of the ECM gene ITGB8 by directly targeting its mRNA three prime untranslated region (3′ UTR). Finally, we found that miR-199-3p overexpression in the GCs of goose pre-hierarchical follicles inhibited the expression of two ECM-related genes (MMP9 and MMP15) yet promoted the expression of another two ECM-related genes (COL4A1 and LAMA1). Taken together, these findings suggest that miR-199-3p participates in granulosa cell migration, viability, and steroidogenesis in goose ovarian follicles before selection by targeting ITGB8 and modulating other ECM-related genes. These data highlight the key roles of miR-199-3p in follicular cell migration, viability, and steroidogenesis by regulating ECM-related genes and thus contribute to a better understanding of the mechanisms underlying follicle selection in birds.

Deformation Replication

1970 ◽  
Vol 28 ◽  
pp. 280-281
Author(s):  
J. Temple Black
Keyword(s):  
Cutting Speed ◽  
Machining Process ◽  
Depth Of Cut ◽  
Rake Face ◽  
Orthogonal Machining ◽  
Aluminum Chips ◽  
Before And After ◽  
Materials Used ◽  
Glass Knife ◽  
Very High

Tool materials used in ultramicrotomy are glass, developed by Latta and Hartmann (1) and diamond, introduced by Fernandez-Moran (2). While diamonds produce more good sections per knife edge than glass, they are expensive; require careful mounting and handling; and are time consuming to clean before and after usage, purchase from vendors (3-6 months waiting time), and regrind. Glass offers an easily accessible, inexpensive material ($0.04 per knife) with very high compressive strength (3) that can be employed in microtomy of metals (4) as well as biological materials. When the orthogonal machining process is being studied, glass offers additional advantages. Sections of metal or plastic can be dried down on the rake face, coated with Au-Pd, and examined directly in the SEM with no additional handling (5). Figure 1 shows aluminum chips microtomed with a 75° glass knife at a cutting speed of 1 mm/sec with a depth of cut of 1000 Å lying on the rake face of the knife.

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