scholarly journals Variation in antral follicle development during the follicular phase of the oestrous cycle in red deer (Cervus elaphus) hinds

Reproduction ◽  
2001 ◽  
pp. 697-705 ◽  
Author(s):  
BJ McLeod ◽  
LM Meikle ◽  
MW Fisher ◽  
TR Manley ◽  
DA Heath ◽  
...  
Keyword(s):  
Granulosa Cells ◽  
Follicular Fluid ◽  
Red Deer ◽  
Antral Follicle ◽  
Follicular Phase ◽  
Oestrous Cycle ◽  
Aromatase Activity ◽  
Follicle Development ◽  
Follicle Diameter ◽  
Follicle Size

The aim of this study was to quantify antral follicle populations in cyclic red deer hinds and to monitor follicle development leading to ovulation. Oestrus was synchronized with exogenous progesterone and ovaries were recovered approximately 0, 12, 24 or 36 h (follicular phase) or 10 days (luteal phase) after progesterone withdrawal (n = 5 per group). All follicles > or = 2 mm in diameter were dissected out, health status was assessed, follicular fluid oestradiol content was measured, granulosa cells were harvested and their capacity for oestradiol and cAMP production was determined. The time of oestrus and the preovulatory LH surge were monitored in five control hinds. Deer ovaries contained 26.6 +/- 3.45 (mean +/- SEM) follicles > or = 2 mm in diameter (range 4-81), with at least one large antral follicle (diameter: 8.3 +/- 0.38 mm) per hind. There was a strong correlation between follicle size and granulosa cell population (r(2) = 0.676). Approximately half (50.7%) of the follicles were classified as healthy, with the percentage classified as atretic decreasing with increasing follicle size. Neither the total number of antral follicles nor their size distribution differed significantly among groups. There were significantly more (P < 0.05) healthy follicles at 24 h after progesterone withdrawal than at 0 h, when large oestrogenic follicles had fewer granulosa cells, lower follicular fluid oestradiol concentrations and lower aromatase activity (P < 0.05) than did those from other groups. In summary, antral follicle development in red deer is similar to that in other monovulatory ruminants, and at least one large follicle is present at all stages of the oestrous cycle.

scholarly journals Gonadotrophin-induced follicle development in red deer hinds during the breeding and non-breeding seasons

Reproduction ◽  
2001 ◽  
pp. 111-119 ◽  
Author(s):  
BJ McLeod ◽  
LM Meikle ◽  
MW Fisher ◽  
GH Shackell ◽  
DA Heath
Keyword(s):  
Health Status ◽  
Follicular Fluid ◽  
Red Deer ◽  
Single Injection ◽  
Antral Follicle ◽  
Chorionic Gonadotrophin ◽  
Follicle Development ◽  
Camp Production ◽  
Breeding Seasons

The effect of exogenous equine chorionic gonadotrophin (eCG) and endogenous (GnRH-treatment) gonadotrophins in promoting antral follicle development in red deer hinds was assessed during the breeding and non-breeding seasons. After progesterone pretreatment, hinds received no further treatment, a single injection of 300 iu equine chorionic gonadotrophin or infusion of GnRH (1.0 microg h(-1)) for up to 4 days. Ovaries were recovered (n = 5 per group) at the time of, or 36 h after, progesterone removal. All follicles > or = 2.0 mm in diameter were dissected out, their health status assessed and follicular fluid oestradiol content measured. Granulosa cells were counted and their capacity for oestradiol and cAMP production assessed in vitro. Oestrus, the preovulatory LH surge and ovulation rates were monitored in additional groups of hinds that had been treated identically (n = 5 per group). During the breeding season, all monitored animals ovulated, but five of 15 (one eCG, three GnRH, one progesterone alone) did not exhibit oestrus, and three (all eCG) had luteinized follicles. During seasonal anoestrus, four hinds (all eCG-treated) displayed oestrus, but only two ovulated. Two non-ovulating hinds (one eCG, one progesterone alone) had luteinized follicles. The total number of follicles, or of large (> or = 4 mm) follicles, did not differ significantly between seasons. There were proportionately more healthy follicles during seasonal anoestrus (P < 0.05). Treatment with GnRH, and to a lesser extent eCG, increased the number of oestrogenic follicles and their follicular fluid oestradiol content. In summary, exogenous and endogenous gonadotrophins affected antral follicle development similarly in both the breeding and non-breeding seasons, although the response was variable among animals and often associated with failure of oestrous expression, ovulation and with follicle luteinization.

Undernutrition during early follicle development has irreversible effects on ovulation rate and embryos

2012 ◽  
Vol 24 (6) ◽  
pp. 886 ◽  
Author(s):  
T. Y. Chen ◽  
P. Stott ◽  
R. Z. Athorn ◽  
E. G. Bouwman ◽  
P. Langendijk
Keyword(s):  
Luteal Phase ◽  
Residual Effect ◽  
Antral Follicle ◽  
Follicular Phase ◽  
Ovulation Rate ◽  
Standard Diet ◽  
Follicle Development ◽  
High Feed ◽  
Irreversible Effects ◽  
Follicle Size

This study assessed carry-over effects of energy level during the early antral phase and subsequent follicular phase on follicle recruitment and ovulation rate. Gilts (n = 45) were fed a standard diet to a low (L, ~1.2 kg day–1) or high (H, ~2.7 kg day–1) level during the early antral (luteal) phase, and subsequently fed a H or L feed level during the follicular phase, resulting in four treatment groups (HH, HL, LH and LL). Follicle size at the end of the luteal phase was greater for gilts fed a high feed level previously (3.3 vs 3.0 mm; P < 0.05). During the follicular phase, high feeding increased follicle size at Day 5 (6.9 vs 6.2 mm; P < 0.005) and plasma oestradiol concentration (P < 0.05). Nevertheless, a low feed level during the luteal phase reduced ovulation rate (14.4 vs 13.2; P < 0.05) and embryo number (12.6 vs 10.5; P < 0.05), and this was not counteracted by feed level during the follicular phase. Plasma progesterone concentration after ovulation was lower for LL gilts than for other treatments (P < 0.05). These results indicate that undernutrition during early antral follicle development may have a residual effect on follicle recruitment and quality.

scholarly journals Heat stress diminishes gonadotropin receptor expression and enhances susceptibility to apoptosis of rat granulosa cells

Reproduction ◽  
2005 ◽  
Vol 129 (4) ◽  
pp. 463-472 ◽  
Author(s):  
Takashi Shimizu ◽  
Izumi Ohshima ◽  
Manabu Ozawa ◽  
Satoko Takahashi ◽  
Atsushi Tajima ◽  
...  
Keyword(s):  
Heat Stress ◽  
Granulosa Cells ◽  
Follicular Fluid ◽  
Follicular Development ◽  
Receptor Expression ◽  
Female Rats ◽  
Aromatase Activity ◽  
Mrna Levels ◽  
Gonadotropin Receptor ◽  
Estradiol Levels

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.

scholarly journals Can the Presence of Ovarian Corpus Luteum Modify the Hormonal Composition of Follicular Fluid in Mares?

Animals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 646
Author(s):  
Katiuska Satué ◽  
Esterina Fazio ◽  
Pietro Medica
Keyword(s):  
Corpus Luteum ◽  
Follicular Fluid ◽  
Jugular Vein ◽  
Blood Samples ◽  
Follicle Diameter ◽  
New Knowledge ◽  
Hormonal Content ◽  
Follicle Size ◽  
Small Follicle

The hypothesis of this study was to investigate if the presence of corpus luteum (CL) in one ovary could modify the hormonal content of follicular fluid (FF) in the follicles. Sixty ovaries were taken after the slaughter of 30 clinically healthy mares. In relation to the sizes, the follicles were classified into three different categories, as small (20–30 mm), medium (31–40 mm) and large (≥41 mm). Blood samples were collected from the jugular vein of mares before their slaughter, and then the FF samplings were extracted from each single follicle. The ovaries that were collected were classified into two groups, according to the presence (CL-bearing) or absence (non-CL-bearing) of CL. The serum and FF samples were analysed for progesterone (P4), oestradiol-17β (E2), testosterone (T), androstenedione (A4) and dehydroepiandrosterone (DHEA). Intrafollicular P4 concentrations in large follicles of CL-bearing groups were lower than for non-CL-bearing ones. Intrafollicular E2 concentrations increased with the increase of the follicle diameter in both groups, CL-bearing and non-CL-bearing. However, in the FF with a large and medium follicle size, E2 concentrations were significantly higher in non-CL-bearing groups than in CL-bearing groups. T and A4 significantly increased in the large and medium follicle sizes when compared to the small follicle sizes in both groups, but higher concentrations in the non-CL-bearing group were obtained. Intrafollicular DHEA significantly decreased with the increase of the follicular diameter in both groups. Steroid hormones in FF dynamically changed, according to the presence or not of CL in the ovary. This study brings new knowledge on the role of the CL in the follicular hormonal composition in mares.

scholarly journals Involvement of miRNAs in equine follicle development

Reproduction ◽  
2013 ◽  
Vol 146 (3) ◽  
pp. 273-282 ◽  
Author(s):  
S N Schauer ◽  
S D Sontakke ◽  
E D Watson ◽  
C L Esteves ◽  
F X Donadeu
Keyword(s):  
Cell Survival ◽  
Granulosa Cells ◽  
Follicular Fluid ◽  
Ovarian Follicle ◽  
Follicle Development ◽  
Previous Evidence ◽  
Ovarian Follicle Development ◽  
Fluid Levels ◽  
Follicle Selection

Previous evidence fromin vitrostudies suggests specific roles for a subset of miRNAs, including miR-21, miR-23a, miR-145, miR-503, miR-224, miR-383, miR-378, miR-132, and miR-212, in regulating ovarian follicle development. The objective of this study was to determine changes in the levels of these miRNAs in relation to follicle selection, maturation, and ovulation in the monovular equine ovary. In Experiment 1, follicular fluid was aspirated during ovulatory cycles from the dominant (DO) and largest subordinate (S) follicles of an ovulatory wave and the dominant (DA) follicle of a mid-cycle anovulatory wave (n=6 mares). Follicular fluid levels of progesterone and estradiol were lower (P<0.01) in S follicles than in DO follicles, whereas mean levels of IGF1 were lower (P<0.01) in S and DA follicles than in DO follicles. Relative to DO and DA follicles, S follicles had higher (P≤0.01) follicular fluid levels of miR-145 and miR-378. In Experiment 2, follicular fluid and granulosa cells were aspirated from dominant follicles before (DO) and 24 h after (L) administration of an ovulatory dose of hCG (n=5 mares/group). Relative to DO follicles, L follicles had higher follicular fluid levels of progesterone (P=0.05) and lower granulosa cell levels ofCYP19A1andLHCGR(P<0.005). Levels of miR-21, miR-132, miR-212, and miR-224 were increased (P<0.05) in L follicles; this was associated with reduced expression of the putative miRNA targets,PTEN,RASA1, andSMAD4. These novel results may indicate a physiological involvement of miR-21, miR-145, miR-224, miR-378, miR-132, and miR-212 in the regulation of cell survival, steroidogenesis, and differentiation during follicle selection and ovulation in the monovular ovary.

scholarly journals Profiling of superoxide dismutase isoenzymes in compartments of the developing bovine antral follicles

Reproduction ◽  
2010 ◽  
Vol 139 (5) ◽  
pp. 871-881 ◽  
Author(s):  
Catherine M H Combelles ◽  
Emily A Holick ◽  
Louis J Paolella ◽  
David C Walker ◽  
Qiaqia Wu
Keyword(s):  
Superoxide Dismutase ◽  
Granulosa Cells ◽  
Follicular Fluid ◽  
Follicular Development ◽  
Cumulus Cells ◽  
Antral Follicle ◽  
Supporting Evidence ◽  
Sod Activity ◽  
Antral Follicles ◽  
Sod Isoforms

The antral follicle constitutes a complex and regulated ovarian microenvironment that influences oocyte quality. Oxidative stress is a cellular state that may play a role during folliculogenesis and oogenesis, although direct supporting evidence is currently lacking. We thus evaluated the expression of the three isoforms (SOD1, SOD2, and SOD3) of the enzymatic antioxidant superoxide dismutase in all the cellular (granulosa cells, cumulus cells, and oocytes) and extracellular (follicular fluid) compartments of the follicle. Comparisons were made in bovine ovaries across progressive stages of antral follicular development. Follicular fluid possessed increased amounts of SOD1, SOD2, and SOD3 in small antral follicles when compared with large antral follicles; concomitantly, total SOD activity was highest in follicular fluids from smaller diameter follicles. SOD1, SOD2, and SOD3 proteins were expressed in granulosa cells without any fluctuations in follicle sizes. All three SOD isoforms were present, but were distributed differently in oocytes from small, medium, or large antral follicles. Cumulus cells expressed high levels of SOD3, some SOD2, but no detectable SOD1. Our studies provide a temporal and spatial expression profile of the three SOD isoforms in the different compartments of the developing bovine antral follicles. These results lay the ground for future investigations into the potential regulation and roles of antioxidants during folliculogenesis and oogenesis.

scholarly journals Effects of oestradiol and progesterone on secretion of gonadotrophins and health of first wave follicles during the oestrous cycle of beef heifers

Reproduction ◽  
2002 ◽  
pp. 531-541 ◽  
Author(s):  
EJ Austin ◽  
M Mihm ◽  
AC Evans ◽  
JL Ireland ◽  
JJ Ireland ◽  
...  
Keyword(s):  
Growth Factor ◽  
Antral Follicle ◽  
Follicle Development ◽  
Dominant Follicle ◽  
Beef Heifers ◽  
Follicle Diameter ◽  
Oestradiol Benzoate ◽  
Lh Release ◽  
Follicle Selection ◽  
Intravaginal Device

Antral follicle development in cattle is initially FSH dependent and then LH dependent. The aim of the present study was to determine the effects of oestradiol- and progesterone-induced suppression of FSH and LH on growth and differentiation of first wave follicles. Cyclic heifers (n = 45, n = 6-10 per group) received the following i.m. injections or treatments beginning 30 h after oestrus: (i) saline (controls); (ii) 0.75 mg oestradiol benzoate (ODB); (iii) insertion of a progesterone-releasing intravaginal device (PRID) for 42 h (progesterone); (iv) 0.75 mg oestradiol benzoate plus PRID (ODB plus progesterone); (v) 0.75 mg ODB plus injection of 1 mg Ovagen(TM) at 33, 39 and 45 h after onset of oestrus (ODB plus FSH). In Expt 1, follicle development was monitored by ovarian ultrasonography once a day. In Expt 2, heifers were ovariectomized. Emergence of the first follicle wave and dominant follicle selection were delayed in ODB plus progesterone-treated heifers compared with controls. Interval to nadir FSH concentration was shorter in ODB-, progesterone- and ODB plus progesterone-treated heifers compared with controls. Frequency of LH pulses was unaffected in ODB- or ODB plus FSH-treated heifers, decreased in progesterone-treated heifers and further decreased in ODB plus progesterone-treated heifers. Intrafollicular oestradiol concentrations were lower in the largest follicle from ODB plus progesterone-treated heifers compared with control (66 h) heifers, but follicle diameter and concentrations of insulin-like growth factor binding proteins (IGFBPs) and inhibin forms were unaffected. Treatment with ODB decreased follicular oestradiol concentration in smaller follicles in the cohort. It is concluded that growing cohort follicles are uniformly responsive to increased FSH concentration but differentially responsive to suppressed FSH and LH release, which is consistent with an LH-mediated survival advantage of the largest follicle in the cohort before cessation of the growth of remaining follicles in the cohort occurs.

scholarly journals Evidence and manipulation of O-GlcNAcylation in granulosa cells of bovine antral follicles†

2021 ◽  
Vol 104 (4) ◽  
pp. 914-923
Author(s):  
Abigail M Maucieri ◽  
David H Townson
Keyword(s):  
Granulosa Cells ◽  
Follicular Fluid ◽  
Nutrient Sensing ◽  
Direct Inhibition ◽  
Antral Follicles ◽  
Cellular Processes ◽  
Hexosamine Biosynthesis ◽  
Follicle Size ◽  
Glcnac Transferase ◽  
Hexosamine Biosynthesis Pathway

Abstract Glucose is a preferred energy substrate for metabolism by bovine granulosa cells (GCs). O-linked N-acetylglucosaminylation (O-GlcNAcylation), is a product of glucose metabolism that occurs as the hexosamine biosynthesis pathway (HBP) shunts O-GlcNAc sugars to serine and threonine residues of proteins. O-GlcNAcylation through the HBP is considered a nutrient sensing mechanism that regulates many cellular processes. Yet little is known of its importance in GCs. Here, O-GlcNAcylation in GCs and its effects on GC proliferation were determined. Bovine ovaries from a slaughterhouse, staged to the mid-to-late estrous period were used. Follicular fluid and GCs were aspirated from small (3–5 mm) and large (&gt;10 mm) antral follicles. Freshly isolated GCs of small follicles exhibited greater expression of O-GlcNAcylation and O-GlcNAc transferase (OGT) than large follicles. Less glucose and more lactate was detectable in the follicular fluid of small versus large follicles. Culture of GCs revealed that inhibition of the HBP via the glutamine fructose-6-phosphate aminotransferase inhibitor, DON (50 μM), impaired O-GlcNAcylation and GC proliferation, regardless of follicle size. Direct inhibition of O-GlcNAcylation via the OGT inhibitor, OSMI-1 (50 μM), also prevented proliferation, but only in GCs of small follicles. Augmentation of O-GlcNAcylation via the O-GlcNAcase inhibitor, Thiamet-G (2.5 μM), had no effect on GC proliferation, regardless of follicle size. The results indicate GCs of bovine antral follicles undergo O-GlcNAcylation, and O-GlcNAcylation is associated with alterations of glucose and lactate in follicular fluid. Disruption of O-GlcNAcylation impairs GC proliferation. Thus, the HBP via O-GlcNAcylation constitutes a plausible nutrient-sensing pathway influencing bovine GC function and follicular growth.

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