Control of FSH, follicular development and estrus synchronization in the mare with steroid-free follicular fluid

1992 ◽  
Vol 37 (4) ◽  
pp. 817-838 ◽  
Author(s):  
H. Plata-Madrid ◽  
W.E. Loch ◽  
R.S. Youngquist ◽  
D.L. Thompson ◽  
K.G. Bennett-Wimbush ◽  
...  
Reproduction ◽  
2000 ◽  
pp. 311-323 ◽  
Author(s):  
JL Hilton ◽  
GE Sarty ◽  
GP Adams ◽  
RA Pierson

The magnetic resonance images and maps of bovine ovaries acquired at defined phases of follicular development and regression were studied to determine whether magnetic resonance image attributes of the follicular antrum reflect the physiological status of dominant and subordinate ovarian follicles. Ovariectomies were performed at day 3 of wave one, day 6 of wave one, day 1 of wave two and at >/= day 17 after ovulation. The timings of ovariectomies were selected to acquire growing, early static, late static and regressing follicles of the first wave and preovulatory follicles of the ovulatory wave. Pre-selection and subordinate follicles were also available for analysis. Serum samples were taken on the day of ovariectomy and follicular fluid samples were taken after imaging. Numerical pixel value and pixel heterogeneity in a spot representing approximately 95% of the follicular antrum were quantified in T(1)- and T(2)-weighted images. T(1) and T(2) relaxation rates (T(1) and T(2)), proton density, apparent diffusion coefficients and their heterogeneities were determined from the computed magnetic resonance maps. The antra of early atretic dominant follicles showed higher T(2)-weighted mean pixel value (P < 0.008) and heterogeneity (P < 0. 01) and lower T(2) heterogeneity (P < 0.008) than growing follicles. Subordinate follicles in the presence of a preovulatory dominant follicle had higher T(1), T(1) heterogeneity, proton density, proton density heterogeneity, and lower mean pixel value in T(1)-weighted images than subordinate follicles of the anovulatory wave (P < 0.04). T(1) relaxation rate heterogeneity and proton density heterogeneity were positively correlated with follicular fluid oestradiol concentration (r = 0.4 and 0.3; P < 0.04). T(2) relaxation rate heterogeneity was positively correlated with follicular fluid progesterone concentration (r = 0.4; P < 0.008). Quantitative differences in magnetic resonance image attributes of the antrum observed among phases of follicular development and regression coincided with changes in the ability of the dominant follicle to produce steroid hormones and ovulate, and thus were indicative of physiological status and follicular health.


Reproduction ◽  
2005 ◽  
Vol 129 (4) ◽  
pp. 463-472 ◽  
Author(s):  
Takashi Shimizu ◽  
Izumi Ohshima ◽  
Manabu Ozawa ◽  
Satoko Takahashi ◽  
Atsushi Tajima ◽  
...  

Heat stress inhibits ovarian follicular development in mammalian species. We hypothesized that heat stress inhibits the function of follicular granulosa cells and suppresses follicular development. To test this, immature female rats were injected with pregnant mare serum gonadotropin (PMSG) at 48 h after the start of temperature treatment (control: 25 °C, 50% RH; heat stress: 35 °C, 70% Relative Humidity). The ovaries and granulosa cells of follicles at different developmental stages were analyzed for gonadotropin receptor levels and aromatase activity; estradiol levels were measured in follicular fluid. Before injection, heat stress diminished only the amount of FSH receptor on granulosa cells of antral follicles. During PMSG-stimulated follicular development, heat stress strongly inhibited gonadotropin receptor levels and aromatase activity in granulosa cells, and estradiol levels in the follicular fluid of early antral, antral and preovulatory follicles. To examine apoptosis and mRNA levels of bcl-2 and bax in granulosa cells, follicles harvested 48 h after PMSG injection were cultured in serum-free conditions. Heat-stressed granulosa cells showed a time-dependent increase in apoptosis. The bcl-2 mRNA levels were similar in control and heat-stressed granulosa cells; bax mRNA levels were increased in heat-stressed granulosa cells. According to these results, heat stress inhibits expression of gonadotropin receptors in granulosa cells and attenuates estrogenic activity of growing follicles, granulosa cells of heat-stressed follicles are susceptible to apoptosis, and the bcl2/bax system is not associated with heat-stress-induced apoptosis of granulosa cells. Our study suggests that decreased numbers and function of granulosa cells may cause ovarian dysfunction in domestic animals in summer.


1995 ◽  
Vol 1995 ◽  
pp. 56-56
Author(s):  
M. Khalid ◽  
W. Haresign

Insulin-like growth factor-1 (IGF-1) is one of the potential autocrine/paracrine regulators of ovarian function. Not only do relationships exist between follicular fluid concentrations of IGF-1 and various biochemical markers of follicular differentiation, but IGF-1 has also been shown to stimulate both proliferation and steroidogenesis in ovarian cells in vitro (Adashi et al., 1985). The actions of IGF-1 are thought to be modulated by IGF-binding proteins (IGFBPs). Indeed, follicular growth and atresia in the ewe have been reported to be determined more by changes in IGFBPs than by changes in IGF-1 (Monget et al., 1993). However, in mat particular study, stage of follicular development was determined by follicle size and by microscopic examination of the granulosa cells of individual follicles rather than by biochemical markers of follicle status. The objective of the present study was, therefore, to investigate changes in IGF-1 and IGFBPs levels in follicular fluid and to relate these to the physiological status as determined by steroidogenic content of follicular fluid.


2014 ◽  
Vol 26 (1) ◽  
pp. 158
Author(s):  
L. Y. Parra-Forero ◽  
G. Vela-Correa ◽  
O. Cano-Flores ◽  
G. Mendoza ◽  
S. Pulido ◽  
...  

The follicular fluid manage and keeps the nutrition of the oocyte and granulosa cell, which are develop inside this liquid. As well this fluid contains growth hormones, growth factors, and some micro-minerals as zinc (Zn). Resources report that Zn could avoid the earlier meiotic detention of the gametes, strengthen the structure of the chromatin due to the discovery of the Zn fingers, while also decrease the oxidative damage and inhibit the electrodes transportation by connecting to the Cytochrome b. The goals of this research were to determine the Zn concentration in the follicular fluid of female horses and define suitable concentration and supplementation in an embryonic culture. The first step of this research was to obtain follicular fluid from 23 female horses; these were classified by follicular size: F1 <1 cm, F2 between 1 and 2 cm, F3 >2 cm. The Zn was measured by spectrophotometry atomic absorption (μg mL–1). The use of the statistics program SAS version 9.3 (SAS Institute Inc., Cary, NC, USA) with a complementary random model, with factorial adjustments. Significance was established when P < 0.001. Obtaining significant differences on the Zn concentration on different follicles (P < 0001). Group F1 0.68 ± 0.15 μg mL–1, F2 1.42 ± 0.17 μg mL–1, and F3 1.8 ± 0,32. Table 1 shows the results of the volume and total concentration. Results indicate that Zn concentration varies with size and maturity of the follicle. Therefore, Zn required to be supplemented could be different as a function of the follicular development; further studies are required to evaluate the embryonic response to Zn addition in different maturation media and to correlate with survival rates. Table 1.Concentration of zinc in fluid follicular of female horses


2017 ◽  
Vol 29 (1) ◽  
pp. 164 ◽  
Author(s):  
W. Huanca ◽  
A. Castro ◽  
N. Gomez ◽  
A. Cordero

Alpacas, like other camelids, are induced ovulators. A study was designed to determine the effect of the ovulation-inducing stimulus on the biochemical composition of follicular fluid. Adult female alpacas (n = 18) were examined daily for 3 days by transrectal ultrasonography using a 5-MHz linear-array transducer (Aloka SSD-500, Tokyo, Japan). When the largest growing ovarian follicle was ≥7 mm, alpacas were given 1.0 mL of seminal plasma intramuscularly (SP, n = 9) or 40 µg of busereline acetate intramuscularly (GnRH, n = 9). A transvaginal transducer with an attached needle guide (Aloka UST-945BP-5) was used for collection of follicular fluid 22 h post-induction. Follicular contents were then centrifuged at 800 × g for 20 min to separate the fluid from the cells. The follicular fluid was collected and stored at –20°C until analysis with a semi-automatic biochemical analyzer (SINOWA, China). The results were glucose 49.17 and 47.95 (mg/dL; P > 0.05), total protein 1.85 and 1.15 (g/dL; P < 0.05), albumin 1.11 and 1.13 (g/dL; P > 0.05), triglycerides 3.94 and 3.16 (mg/dL; P > 0.05), cholesterol 39.01 and 42.5 (mg/dL; P > 0.05), phosphatase 32.68 and 21.36 (IU/L; P < 0.05), alanine aminotransferase 3.66 and 5.07 (IU/L; P > 0.05), and lactate dehydrogenase 42.17 and 27.27 (IU/L; P > 0.05) for SP or GnRH treatments, respectively. Results suggest the need to continue research to explain the effect of possible differences in total protein, cholesterol, and phosphatase on oocyte-expressed genes and follicular development. Research was supported by the project no. 405-PNICP-PIAP-2014-UNMSM.


1997 ◽  
Vol 154 (1) ◽  
pp. 35-43 ◽  
Author(s):  
S C Cwyfan Hughes ◽  
H D Mason ◽  
S Franks ◽  
J M P Holly

Abstract The IGFs are believed to play an important role in the regulation of steroidogenesis and follicular maturation in the human ovary. The activities of the IGFs are regulated by a family of binding proteins (IGFBPs) which are subject to a number of potential post-translational modifications. The aim of this study was to investigate both the production and modification of the IGFBPs in follicular fluid and in medium conditioned by granulosa cells and theca from individual follicles at different stages of maturation. In follicular fluid from healthy, dominant follicles there was an increase in the amount of IGFBP-2, -3 and -4 present as lower molecular weight forms (23 kDa, 29 kDa and 16·5 kDa respectively) in comparison to that seen in atretic follicles from the same ovary. Furthermore for IGFBP-4, this fragmentation was confirmed to be attributable to the presence of a specific protease which could be inhibited not only by the addition of metal ion chelators or serine protease inhibitors, but also by the addition of other recombinant unsaturated IGFBPs, particularly IGFBP-3. IGF-I did not modulate the activity of the IGFBP-4 protease in solution but was able to prevent the inhibition seen with IGFBP-3. Analysis of granulosa cell conditioned medium from the same series of healthy and atretic follicles revealed that IGFBP-2 and -4 were the predominant IGFBPs with no fragments seen on immunoblotting. In contrast, IGFBP-3 in conditioned medium from theca of atretic follicles was always found as an intact doublet, but was found partially fragmented (30 and 32 kDa) in medium conditioned by theca from healthy, dominant follicles with the proportion of IGFBP-3 in this lower molecular weight or fragmented doublet increasing with follicular maturation. A similar situation was also found for IGFBP-4 with the progressive increase in the amount of the 15 and 16·5 kDa fragments. IGFBP-2 was always found to be intact. Finally, IGFBP production from stroma explants was also examined. This revealed a wide variation in IGFBP pattern between different ovaries, although there was a remarkable degree of consistency between different stroma explant cultures from the same ovary. Immunoblotting for IGFBP-3 revealed that, where present, it existed as both an intact and a lower molecular weight doublet and that IGFBP-2 was again always found to be intact. In conclusion we have demonstrated alterations in the proteolytic modification of the IGFBPs which differ in the various follicular compartments and are closely linked to the stage of follicular development. Journal of Endocrinology (1997) 154, 35–43


2001 ◽  
Vol 72 (3) ◽  
pp. 547-554 ◽  
Author(s):  
A.C.O. Evans ◽  
P. Duffy ◽  
K. M. Quinn ◽  
P. G. Knight ◽  
M. P. Boland

AbstractThe aim was to examine statistically the changes among days in the numbers of follicles relative to the growth of large follicles to test the hypothesis that follicular development occurs in a wave-like fashion in anoestrous ewes. The relationships among the patterns of circulating concentrations of FSH, oestradiol and inhibin-A and the pattern of follicular growth as well as relationships among follicular fluid steroid and inhibin-A concentrations were also studied. The ovaries of 11 ewes were examined daily using transrectal ultrasonography for 14 days and blood samples were collected every 8 h for 9 days. Five ewes were ovariectomized on the last day of ultrasound scanning. One to three identified follicles (a cohort) emerged every 2 to 5 days (mean 2·9 (s.e. 0·2) days) in individual ewes. The numbers of 4 and 5 mm follicles were fewest (P < 0·05) before and greatest (P < 0·05) 1 day after cohort emergence. This change in the numbers of follicles indicates a wave-like pattern of follicular growth. FSH concentrations were greatest (P < 0·05) on the day before wave emergence and lowest (P < 0·05) on the day of wave emergence. Peripheral concentrations of oestradiol and inhibin-A did not fluctuate (P > 0·05) in association with the emergence of follicular waves. The follicles that were collected at ovariectomy originated from one of three different waves. Oestradiol and inhibin-A concentrations in follicular fluid and the oestradiol-to-progesterone ratio were not different among the largest follicles of successive waves, when follicles were collected at the same time, indicating that new waves of follicles developed before the demise of old waves.In conclusion, waves of follicles emerged about every 3 days in anoestrous ewes (defined as significant changes in numbers of follicles) and were associated with fluctuations in FSH concentrations but not peripheral oestradiol or inhibin-A concentrations. New follicular waves also emerged in the presence of steroidogenically active (positive oestradiol-to-progesterone ratio), inhibin-A producing follicles from a previous wave suggesting that follicles do not exert functional dominance during the non-breeding season.


Endocrinology ◽  
2017 ◽  
Vol 159 (2) ◽  
pp. 710-722 ◽  
Author(s):  
Hannah R Bender ◽  
Heidi A Trau ◽  
Diane M Duffy

Abstract Placental growth factor (PGF) is member of the vascular endothelial growth factor (VEGF) family of angiogenesis regulators. VEGFA is an established regulator of ovulation and formation of the corpus luteum. To determine whether PGF also mediates aspects of ovulation and luteinization, macaques received gonadotropins to stimulate multiple follicular development. Ovarian biopsies and whole ovaries were collected before (0 hours) and up to 36 hours after human chorionic gonadotropin (hCG) administration to span the ovulatory interval. PGF and VEGFA were expressed by both granulosa cells and theca cells. In follicular fluid, PGF and VEGFA levels were lowest before hCG. PGF levels remained low until 36 hours after hCG administration, when PGF increased sevenfold to reach peak levels. Follicular fluid VEGFA increased threefold to reach peak levels at 12 hours after hCG, then dropped to intermediate levels. To explore the roles of PGF and VEGFA in ovulation, luteinization, and follicular angiogenesis in vivo, antibodies were injected into the follicular fluid of naturally developed monkey follicles; ovariectomy was performed 48 hours after hCG, with ovulation expected about 40 hours after hCG. Intrafollicular injection of control immunoglobulin G resulted in no retained oocytes, follicle rupture, and structural luteinization, including granulosa cell hypertrophy and capillary formation in the granulosa cell layer. PGF antibody injection resulted in oocyte retention, abnormal rupture, and incomplete luteinization, with limited and disorganized angiogenesis. Injection of a VEGFA antibody resulted in oocyte retention and very limited follicle rupture or structural luteinization. These studies demonstrate that PGF, in addition to VEGFA, is required for ovulation, luteinization, and follicular angiogenesis in primates.


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