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1.
Endometrial expression of oestrogen receptor‐α (ERα), progesterone receptor (PR) and cyclooxigenase‐2 (COX‐2) was evaluated in non‐pregnant and pregnant llamas during the period when luteolysis/maternal recognition of pregnancy is expected to occur. Females (n = 28) were divided into two groups: non‐pregnant llamas were induced to ovulate with a Buserelin injection, and endometrial biopsies were obtained on day 8 (n = 5) or 12 (n = 5) post‐induction of ovulation. Animals of the pregnant group (n = 18) were mated with a fertile male. Pregnancy was confirmed by the visualization of the embryo collected by transcervical flushing in 5 of 9 animals on day 8 post‐mating and by progesterone profile on day 12 post‐mating in 4 of 9 animals, when endometrial biopsies were obtained. An immunohistochemical technique was used to evaluate receptors population and COX‐2 expression. Pregnant llamas showed a higher percentage of positive cells and stronger intensity for ERα than for non‐pregnant llamas in stroma on day 8 and in the luminal epithelium on day 12 post‐induction of ovulation, while a deep decrease in endometrial PR population was reported in pregnant llamas on that day in luminal and glandular epithelia and stroma. In the luminal epithelium, COX‐2 expression was lower in pregnant than in non‐pregnant animals. Briefly, the increase of ERα in pregnant llamas gives further support to the hypothesis that oestrogens are involved in the mechanism of maternal recognition of pregnancy. Endometrial PR decrease in pregnant llamas might be a necessary event to allow the expression of proteins involved in conceptus attachment, a mechanism widely accepted in other species. Moreover, embryo seems to attenuate maternal PGF2α secretion during early pregnancy by decreasing the endometrial expression of COX‐2 in the luminal epithelium of pregnant llamas.  相似文献   

2.
This study evaluated the effects of follicular phase administration of TAK‐683, an investigational metastin/kisspeptin analog, on follicular growth, ovulation, luteal function and reproductive hormones in goats. After confirmation of ovulation by transrectal ultrasonography (Day 0), PGF2α (2 mg/head of dinoprost) was administered intramuscularly on Day 10 to induce luteal regression. At 12 h after PGF2α administration, intravenous administration of vehicle or 35 nmol (50 μg)/head of TAK‐683 was performed in control (n = 4) and treatment (n = 4) groups, respectively. Blood samples were collected at 6‐h intervals for 96 h and then daily until the detection of subsequent ovulation (second ovulation). After the second ovulation, ultrasound examinations and blood sampling were performed every other day or daily until the subsequent ovulation (third ovulation). Mean concentrations of LH and FSH in the treatment group were significantly higher 6 h after TAK‐683 treatment than those in the control group (12.0 ± 10.7 vs 1.0 ± 0.7 ng/ml for LH, 47.5 ± 28.2 vs 15.1 ± 3.4 ng/ml for FSH, p < 0.05), whereas mean concentrations of oestradiol in the treatment group decreased immediately after treatment (p < 0.05) as compared with the control group. Ovulation tended to be delayed (n = 2) or occurred early (n = 1) in the treatment group as compared with the control group. For the second ovulation, ovulatory follicles in the treatment group were significantly smaller in maximal diameter than in the control group (3.8 ± 0.5 vs 5.4 ± 0.2 mm, p < 0.05, n = 3). Administration of TAK‐683 in the follicular phase stimulates gonadotropin secretion and may have resulted in ovulation of premature follicles in goats.  相似文献   

3.
Interest in indicus–taurus cattle has been increasing, as these animals are likely to present the best characteristics of Zebu and European bovine breeds. The aim of this study was to compare the embryo production of indicus–taurus donors with high vs low antral follicle counts obtained by ovum pickup/in vitro production (OPU/IVP) and superovulation (SOV)/embryo collection. Braford females at weaning age (3/8 Nelore × 5/8 Hereford, n = 137, 9 ± 1 month old) were subjected to six serial ovarian ultrasonographs and were assigned to two groups according to the number of antral follicles ≥3 mm as follows: G‐High antral follicular count (AFC, n = 20, mean ≥40 follicles) and G‐Low AFC (n = 20, mean ≤10 follicles). When the females (n = 40) reached 24 months of age, they were subjected to both OPU/IVP and SOV/embryo collection. The average number of follicles remained highly stable throughout all of the ultrasound evaluations (range 0.90–0.92). The mean number of COCs recovered (36.90 ± 13.68 vs 5.80 ± 3.40) was higher (p < 0.05) for females with high AFC, resulting in higher (p < 0.05) numbers of total embryos among females with high vs low AFC (6.10 ± 4.51 vs 0.55 ± 0.83). The mean number of embryos per collection was also higher (p < 0.05) for G‐High vs G‐Low (6.95 ± 5.34 vs 1.9 ± 2.13). We conclude that a single ultrasound performed at pre‐pubertal ages to count antral follicles can be used as a predictor of embryo production following IVP and SOV/embryo collection in indicus–taurus females.  相似文献   

4.
In this study, alteration in the follicular fluid composition and luteal function was investigated in the buffalo with endometritis. Genitalia were classified into cytological and purulent endometritis on the basis of polymorphonuclear cell cut off while non‐endometritis served as control (n = 10/group). In the follicular phase, the number of surface follicles was counted, diameter of the largest follicle was measured and the follicular fluid was assayed for total protein, cholesterol, malondialdehyde (MDA), total antioxidant capacity (TAC), oestradiol (E2) and progesterone (P4). The P4 content of corpus luteum during mid‐luteal phase was estimated by radioimmunoassay. Ovaries from the follicular phase of oestrous cycle showed no significant difference in the total number of surface follicles, size of the largest follicle and volume of follicular fluid in the buffaloes with and without endometritis (p > .05). However, the antral fluid of the largest follicle from the genitalia of buffalo with cytological and purulent endometritis showed a significant decrease in the concentration of total protein, cholesterol, TAC and E2 and a significant increase in the concentration of MDA and P4 (p < .05). The results indicated that there is an association between endometritis and decreased ovarian function.  相似文献   

5.
The objective was to compare populations of antral and pre‐antral ovarian follicles in Bos indicus and Bos indicus‐taurus cows with high and low antral follicle counts. Nelore (Bos indicus, n = 20) and Nelore X Angus (1/2 Bos indicus‐taurus, n = 20) cows were subjected to follicular aspiration without regard to the stage of their oestrous cycle (day of aspiration = D0) to remove all follicles ≥3 mm and induce growth of a new follicular wave. Ovaries were examined by ultrasonography on D4, D19, D34, D49 and D64, and antral follicles ≥3 mm were counted. Thereafter, cows were assigned to one of two groups: high or low antral follicular count (AFC, ≥30 and ≤15 antral follicles, respectively). After D64, ovaries were collected after slaughter and processed for histological evaluation. There was high repeatability in the numbers of antral follicles for all groups (range 0.77–0.96). The mean (±SD) numbers of antral follicles were 35 ± 9 (Bos indicus) and 38 ± 6 (Bos indicus‐taurus) for the high AFC group and 10 ± 3 (Bos indicus) and 12 ± 2 (Bos indicus‐taurus) follicles for the low AFC. The mean number of preantral follicles in the ovaries of Bos indicus‐taurus cows with high AFC (116 226 ± 83 156 follicles) was greater (p < 0.05) than that of Bos indicus cows (63 032 ± 58 705 follicles) with high AFC. However, there was no significant correlation between numbers of antral and preantral follicles.  相似文献   

6.
The hypothesis that a local serotonergic network might also exist in the follicle of mares remains poorly documented, with exception for humans and laboratory species. For this reason, the aim of the present study was to clarify this possibility, investigating intrafollicular serotonin concentrations of the cycling mare at ovulation time. Sixty ovaries collected from 30 clinically healthy mares of slaughterhouse meat production with clinically normal reproductive tracts after slaughtering were evaluated. Blood samples were taken prior to sacrifice. Follicles were classified in three categories in relation to size, as small (20–30 mm), medium (31–40 mm) and large (>41 mm), and the follicular fluid samples were extracted from each follicle. Intrafollicular and systemic serotonin (5‐HT), oestradiol‐17β (E2) and progesterone (P4) were determined by means of enzyme‐linked immunosorbent assay and RIA, respectively. Intrafollicular 5‐HT, E2 and P4 concentrations were higher than systemic ones (p < .05). 5‐HT concentrations increased in larger compared to medium follicles, without differences compared to small size follicles (p < .05). 5‐HT and E2 (r = .79) and 5‐HT and P4 (r = .79; p < .05) were positively correlated. 5‐HT and P4 concentrations in follicular fluid increased progressively with the increase in follicular size (p < .05). Follicle diameter and E2 (r = .85) and P4 (r = .68) were correlated (p < .05). Since serotonin interacts with steroids, its role on steroidogenesis during growth of the dominant follicle may be suggested.  相似文献   

7.
The aim of this study was to compare the effect of the intramuscular administration of 50 μg of gonadorelin acetate versus natural mating, intrauterine infusion (i.u.) of a physiological relevant dose of either raw llama seminal plasma (SP) or purified beta‐nerve growth factor from seminal origin (spβ‐NGF) on ovulation rate and corpus luteum (CL) development and function in llamas. Females with a follicle (≥8 mm) were assigned to groups: (i) i.m. administration of 50 μg of gonadorelin acetate (GnRH; positive control; n = 4); (ii) single mating (mating; n = 6); (iii) i.u. infusion of 4 ml of llama SP (SP; n = 4); or (iv) i.u. infusion of 10 mg of spβ‐NGF contained in 4 ml of PBS (phosphate‐buffered saline) (spβ‐NGF; n = 6). Ovaries were examined by power Doppler ultrasonography at 0, 1, 3, 6, 12 and 24 hr after treatment to determine preovulatory follicle vascularization area (VA), and additionally every 12 hr until Day 2 (Day of treatment = Day 0) to determine ovulation. Afterwards, ovaries were examined every other day until Day 8 to evaluate CL diameter and VA. Blood samples were collected on Days 0, 2, 4, 6 and 8 to determine plasma progesterone (P4) concentration. Ovulation rate did not differ (p = .7) among groups, but treatment affected (p < .0001) preovulatory follicle VA. Neither treatment administration nor treatment by time interaction affected (p ≥ .4) CL diameter, VA and plasma P4 concentration. Mating tended (p = .08) to increase CL VA when compared to the seminal plasma group by Day 8. Intrauterine administration of seminal plasma or spβ‐NGF does not increase CL size and function when compared to i.m. GnRH treatment, suggesting that the administration route of spβ‐NGF influences its luteotrophic effect in llamas.  相似文献   

8.
The aim of this study was to evaluate luteal dynamics in the Santa Inês ewes using colour Doppler (CD) ultrasonography. Oestrus was synchronized in nulliparous females (n = 18), and subsequently, they were only teased (n = 6) or teased and mated (n = 12). Blood samples were collected daily for plasma progesterone (P4) concentrations. Ultrasonographic images of corpora lutea (CL) in CD mode were obtained for further analysis in its largest diameter. The CD mode allowed an early sequential monitoring of CL that was visualized by the first time 0.77 ± 0.62 days after ovulation, with luteal area 29.68 ± 13.21 mm2. During the luteogenesis, a progressive increase was observed, followed by a plateau of luteal area, vascularization area and plasma concentrations of P4 reaching maximum values in D11 (124.0 ± 38.0 mm2, 52.78 ± 24.08 mm2 and 11.23 ± 4.89 ng/ml, respectively). In the luteolysis, the plasma concentrations of P4 decreased sharply, whereas luteal and vascularization area gradually. The vascularization area was positively correlated with plasma concentrations of P4 during the luteogenesis (r = 0.22) and luteolysis (r = 0.48). The luteal dynamics of Santa Inês ewes showed patterns similar to those observed in other sheep breeds studied. The CD ultrasonography has the potential to be used as a tool to assess luteal function in sheep.  相似文献   

9.
Very small follicles (<3.0 mm diameter) are over‐represented on the surface of ovaries of non‐cycling pigs, and the oocytes collected from these follicles generally have reduced developmental competence in vitro. This study examined the effect of follicle size on the nuclear maturation (n = 608), the potential of parthenogenetic activation (n = 243) and the cyclic AMP (cAMP) content of pre‐pubertal porcine oocytes (n = 480). In addition, the influence of follicle size on steroid hormone synthesis was analysed. Cumulus oocyte complexes (COCs) flushed from small (2.5–4.0 mm) or large (4.5–6.0 mm) ovarian follicles were cultured for 0, 28 and 46 h. After 46 h of IVM, a greater proportion of oocytes from 4.5‐ to 6.0‐mm follicles reach metaphase II (MII) compared with those from follicles with 2.5–4.0 mm of diameter (96.1 vs 77.0%, respectively; p < 0.001). Parthenogenetic activation of oocytes from large follicles produced higher developmental rates than oocytes from large follicles (p < 0.05). At 28 h, the IVM medium with oocytes from large follicles contained significantly more 17ß‐oestradiol (E2) than the medium with oocytes from small follicles (5.55 vs 3.45 ng/ml, respectively; p < 0.05) and at 46 h, the medium with oocytes from small follicles contained significantly more progesterone (P4) than the medium with oocytes from large follicles (276.7 vs 108.2 ng/ml, respectively, p < 0.05). Porcine oocytes from large follicles have higher nuclear and cytoplasmic maturation capacities, but the differences did not appear to be cAMP‐mediated. Our findings also suggest that COCs from small follicles undergo more intensive luteinization than COCs from large follicles. The results show that oocytes from follicles with a diameter greater than 4.0 mm are more suitable for in vitro studies.  相似文献   

10.
Capromorelin is a ghrelin receptor agonist that is FDA approved for appetite stimulation in dogs. The objective of this study was to evaluate the safety of daily oral administration of capromorelin to cats over a range of doses and for an extended period. Two randomized, controlled studies were conducted: in Study 1, cats (n = 6 per group) received placebo or capromorelin at a dose of 9, 15, 30 or 60 mg/kg once daily for 14 days; and in Study 2, cats received capromorelin at 6 mg/kg (n = 8) or placebo (n = 4) once daily for 91 days. Cats were evaluated using clinical observations and clinical pathology test results for both studies, with the addition of postmortem examination in Study 1 and measurements of growth hormone and insulin‐like growth factor 1 in Study 2. Abnormal clinical observations were limited to emesis, hypersalivation, lethargy/depression, head shaking and lip smacking, which occurred more frequently in the capromorelin‐treated groups than in the placebo group. There were no clinically relevant differences in clinical pathology test results between the capromorelin and placebo groups in either study.  相似文献   

11.
Ovarian follicular growth in non‐mated llamas occurs in successive waves that generally superimpose their origin on the regression of the preceding wave (overlapping), originating prolonged sexual receptivity in the species. The aim of this study was to perform an ultrasonographic and endocrine characterization of individual and successive waves in non‐mated llamas with a special interest on the overlapping phenomenon. Twelve llamas were examined daily by transrectal ultrasonography for at least two consecutive waves. In six females, blood samples were collected daily at the end of each examination. The development of the largest follicle (F) showed a wavelike pattern with a mean duration of 25 days. All waves evaluated were partially overlapped on the preceding wave and emerged at a mean interval of 15.8 ± 0.5 days. This interwave interval determines a mean overlapping degree of 32% of the wave length. Similarly, mean plasma oestradiol‐17β (E2) concentrations followed a wavelike pattern. However, E2 concentrations started to decline before the structural regression of the F was observed. Mean basal E2 concentrations remain higher than 10.9 ± 0.6 pmol/l. In conclusion, follicular activity in non‐mated llamas is characterized by continuous emergence of successive waves that always overlap the preceding wave with variable degrees. E2 production during the follicular wave is shorter in duration than the morphological development of the F. Finally, the overlapping phenomenon maintains increased plasma E2 concentrations persistently and this could explain the prolonged periods of sexual receptivity registered in llamas.  相似文献   

12.
The aim was to study postpartum follicular population dynamics in Brahman cows in the Mexican humid tropics and under different stocking rates. Lactating adult cows (n = 104) grazed native grammas (Paspalum spp., Axonopus spp.) under two stocking rates: 2.8 (high) or 1.7 (low) cows/ha. Follicle numbers and their size (millimetres) were measured by ovarian ultrasound scanning. Animals detected in oestrus and inseminated were taken out of the study. Both stocking rates produced similar (P < 0.05) body condition scores (BCS) and follicular dynamics. The percent of follicles, averaged over stocking rates, of <4 mm diminished and those of 5–8 mm increased with time, whilst those of >9 mm remained constant; respective values for the previously mentioned sizes were 60 days postpartum (n = 101), 49%, 56% and 5%; 120 days (n = 70), 28%, 66% and 6%; and 180 days (n = 15), 9%, 79% and 12%. There was a positive correlation between BCS and follicle number for size <4 mm (r = 0.73, P < 0.01), whilst for size 5–8 mm, this was negative (r = −0.51, P < 0.05), for follicles >9 mm, no difference was found (r = −0.08, P > 0.05). It was concluded that stocking rate did not affect follicular population dynamics of Brahman cows, but BCS dictated the number and categories of follicles present regardless of the stocking rate utilised.  相似文献   

13.
Carotenoids are lipid‐soluble pigments and important for a variety of physiological functions. They are major dietary vitamin A precursors and act as lipophilic antioxidants in a variety of tissues and are associated with important health benefits in humans and animals. All animals must acquire carotenoids from their diet, but to our knowledge, there are no studies investigating the intestinal carotenoid absorption and their blood concentrations in New World camelids. The present study aimed to assess the serum concentrations of selected carotenoids in llamas (n = 13) and alpacas (n = 27). Serum carotenoids as well as retinol (vitamin A) and α‐tocopherol (vitamin E) were determined by high‐performance liquid chromatography coupled with mass spectrometry and these were unable to detect any carotenoids (α‐ and β‐carotene, α‐ and β‐cryptoxanthin, lutein, zeaxanthin, lycopene) in the samples. The concentrations of retinol in alpacas (2.89 ± 1.13 μmol/l; mean ± SD) were higher (p = 0.024) than those found in llamas (2.05 ± 0.87 μmol/l); however, the concentrations of α‐tocopherol were not significantly (p = 0.166) different (llamas: 3.98 ± 1.83 μmol/l; alpacas: 4.95 ± 2.14 μmol/l). The results show that both llamas and alpacas are not able to absorb intact carotenoids, but efficiently convert provitamin A carotenoids to retinol.  相似文献   

14.
The aim of this study was to verify the effect of the energy source for a short‐term diet supplementation on follicular dynamics, ovarian response and oocyte recovery in goats. Thirty Anglo Nubian crossbred does received a diet for 4 weeks to satisfy the nutritional requirements of breeding for adult non‐dairy goats. Seven days prior to oocyte recovery (OR), a group of does (n = 10) was supplemented with ground full‐fat linseed in the diet (Diet A), whereas a second group of does (n = 10) received crude glycerine in the diet (Diet B). The total mixed ration (TMR) diet was maintained as the Control Diet (n = 10). All animals were oestrous‐synchronized by the use of a progesterone insert for 12 days prior to OR. Follicles were stimulated by using pFSH (five 40‐mg/ml doses) during the supplementation time. At OR, follicles were counted and recovered oocytes were classified as viable or degenerated. Follicular dynamics was monitored by ultrasonography, and plasma glucose, cholesterol and triglyceride levels were measured during supplementation. Glucose was higher in Diet B and cholesterol in Diet A. Diet B had a lower proportion of small (<3 mm) and large follicles (≥3 mm; p = 0.01). The follicular growth rate was higher in Diet A (p < 0.01), with follicles emerging in the 5th day of supplementation. No differences were observed for follicles counted and oocytes recovered. Thus, the type of energy source supplemented for a short term was capable to alter the follicular dynamics, without affecting the proportion of morphologically viable oocytes upon recovery.  相似文献   

15.
Two experiments were undertaken to select the efficient method applied for goat estrous synchronization. In experiment 1, a total of 120 does (Capra hircus) were divided into five groups with a randomized block design, and the does of treatment 1 were synchronized by intravaginal sponges impregnated with 30 mg Levonorgestrel inserted for 10 days. Does of treatments 2, 3, and 4 were treated with further injection of 25 IU follicle-stimulating hormone (FSH), 0.05 mg prostaglandin F2 alpha (PGF2α), and 25 IU FSH + 0.05 mg PGF2α at sponge withdrawal, respectively. The does in the control group (n = 40) without estrous synchronization treatment and natural estrous does were observed. In experiment 2, a total of 140 does in five goat farms in breeding and non-breeding seasons were treated with the selective efficient procedure. The results presented that all the employed treatments were capable of inducing and synchronizing estrous goats. According to estrous response and economy, the use of intravaginal sponges impregnated with 30 mg Levonorgestrel and 0.05 mg PGF2α (treatment 3) is the first choice for estrous synchronization, and 95.0% of synchronized does demonstrated estrus, which was significantly higher than that of treatment 1 (P < 0.05) and control group (P < 0.01). The percentages of ovulating of treatments 3 and 4 were the same (95.0%), which were significantly higher than that of treatment 1 (P < 0.01). The ovulation rates among different groups were not significant (P > 0.05). When the selective procedure was applied to five goat farms, 85.7% (120/140) of does demonstrated estrus, and the kidding percentage, litter size, and prolificacy rate were 53.6%, 0.95, and 177%, respectively.  相似文献   

16.
The objective of this study was to examine the follicular characteristics and intrafollicular concentrations of nitric oxide and ascorbic acid during ovarian acyclicity in buffaloes. Ovaries were collected from 56 acyclic and 95 cyclic buffaloes at slaughter, surface follicle number was counted and follicles were classified into small (5.0–6.9 mm), medium (7.0–9.9 mm), and large (≥10.0 mm) size categories based on their diameter. Follicular fluid was aspirated and assayed for nitric oxide, ascorbic acid, estradiol, and progesterone. Acyclic buffaloes had a higher (P < 0.05) number of medium-sized follicles and a lower (P < 0.001) number of large follicles than the cyclic ones. In acyclic animals, the number of large follicles was lower (P < 0.01) than in medium size category which in turn was lower (P < 0.001) than the number of small follicles. In contrast, the number of medium and large follicles was not different (P > 0.05) in the cyclic control. However, the number of small-sized follicles was higher (P < 0.001) compared to the other two categories. The incidence of large-sized follicles was lower (P < 0.05) in acyclic buffalo population compared to the cyclic control. Evaluation of estrogenic status demonstrated that all the follicles of acyclic buffaloes are estrogen-inactive (E 2/P 4 ratio < 1). Small- and medium-sized follicles of acyclic buffaloes had higher concentrations of nitric oxide (P < 0.05 and P < 0.001, respectively) and lower concentrations of ascorbic acid (P < 0.05 and P < 0.01, respectively) than the corresponding size estrogen-active follicles of their cyclic counterparts. In conclusion, this study indicates that follicular development continues during acyclicity in buffaloes. Although follicles in some acyclic buffaloes attain a size corresponding to morphological dominance, they are unable to achieve functional dominance, perhaps due to an altered balance of intrafollicular nitric oxide and ascorbic acid and, as a result, these follicles instead of progressing to ovulation undergo atresia.  相似文献   

17.
Ovarian response of collared peccaries (Pecari tajacu), after hormonal stimulation with gonadotropin association (eCG/hCG), was accessed by both gene expression and follicular development. Thus, collared peccaries (n = 8) were treated with the dose used for sows (swine dose, SWD) or with dose adjusted for peccary's weight (allometric dose, ALD). The gene expression of receptors was evaluated for both gonadotropins (FSHR and LHCGR) and growth factors (proteins codified by TGFβR-1, BMPR1-A and BMPR2 genes) in antral follicles, cortex and corpora haemorrhagica (CH). Five days after gonadotropin injection, all females presented CH. The ovulation rate was similar (p > .05) between SWD (4.00 ± 1.17) and ALD (2.50 ± 0.43) group. The total number of follicles per animal and amounts of small (<3 mm), medium (3–5 mm) and large (>5 mm) follicles was similar among groups. However, SWD produced large follicles heavier than ALD group, as accessed by weight of follicular wall biopsies. Ovarian follicles expressed both gonadotropin and growth factor receptors at levels which are independent from gonadotropin dose. In conclusion, the two gonadotropin doses (SWD and ALD) can be used for ovarian stimulation of collared peccary. Additionally, FSH and growth factors (TGFβR-1, BMPR1-A and BMPR2) receptors are more expressed in the early follicle development, while LH receptor seems to be more important in the final of follicular growth.  相似文献   

18.
The anti‐Müllerian hormone (AMH) is an important marker of ovarian reserve and for predicting the response to superovulatory treatments in several species. The objective of this study was to investigate whether AMH and its receptor (AMHR2) are regulated in bovine granulosa cells during follicular development. In the first experiment, granulosa cells were retrieved from the two largest follicles on days 2 (before), 3 (at the expected time) or 4 (after deviation) of follicular wave. In the second experiment, four doses of FSH (30, 30, 20 and 20 mg) or saline were administered twice a day starting on Day 2 of the first follicular wave of the cycle. Granulosa cells and follicular fluid were collected from the two largest follicles 12 h after the last injection of FSH or saline. AMH mRNA abundance was similar in granulosa cells of the two largest follicles (F1 and F2) before deviation (Day 2), but greater in dominant (DF) than subordinate follicles (SF) at the expected time (Day 3) and after (Day 4) deviation (p < 0.05). In experiment 1, AMH mRNA levels declined in both DF and SF near the expected time and after deviation when compared to before deviation. There was no difference in AMHR2 mRNA levels before and during follicular deviation (p > 0.05), but they tended to be greater in DFs than SFs (p < 0.1) after deviation. Experiment 2 showed that AMH and AMHR2 mRNA in granulosa cells and AMH protein abundance in follicular fluid were similar (p > 0.05) between both co‐dominant follicles collected from the FSH‐treated cows. These findings indicate the followings: AMH mRNA levels decrease in both DFs and SFs during follicular deviation; granulosa cells from heathy follicles express more AMH mRNA compared to subordinate follicles undergoing atresia and FSH stimulates AMH and AMHR2 mRNA expression in granulosa cells of co‐dominant follicles.  相似文献   

19.
In Bos taurus cattle, antimullerian hormone (AMH) has been demonstrated to have a high degree of correlation with ovarian antral follicle count and the number of healthy follicles and oocytes. To document the correlation between the plasma concentration of AMH and follicular number in Bos indicus and Bos taurus heifers, Nelore (Bos indicus, n = 16) and Holstein heifers (Bos taurus, n = 16) had their ovarian follicular waves synchronized. After synchronization, ovarian antral follicular population (AFP) was evaluated three times at 60‐day (d) intervals (T‐120 d, 120 days before plasma AMH determination; T‐60 d, 60 days before; and T0, at the time of plasma AMH determination). The plasma AMH concentration was positively correlated with the number of ovarian follicles on the day of the follicular wave emergence in Bos indicus (Nelore) and Bos taurus (Holstein) heifers at each evaluation time (p < 0.05). The AFP was higher in Bos indicus (Nelore) than in Bos taurus (Holstein) heifers (p < 0.05). Similarly, the AMH concentration was higher in Bos indicus (Nelore) than in Bos taurus (Holstein) heifers (p < 0.0001). When heifers were classified as to present high or low AFP according to the mean of the AFP within each genetic group, high‐AFP heifers presented a greater (p < 0.0001) AMH concentration than low‐AFP heifers, regardless of the genetic group. In conclusion, the AFP is positively correlated with plasma AMH concentration in both Bos indicus (Nelore) and Bos taurus (Holstein) heifers. Furthermore, Bos indicus (Nelore) heifers presented both greater plasma AMH concentrations and AFP than Bos taurus (Holstein) heifers.  相似文献   

20.
The aim of this study was to evaluate the effect of leptin administration during superovulation on in vivo goat embryo production. Ten mature does were superovulated with 133 mg follicle‐stimulating hormone (FSH) i.m. in six descending doses at 12‐h intervals. The goats received 4.8 μg/kg human recombinant leptin s.c. (leptin group, n = 5) or phosphate‐buffered saline (PBS) (control group, n = 5) with the first and second FSH doses. The does were mated and subjected to embryo collection by transcervical technique 6 days later. The total number of cells per embryo and the number of cells with fragmented DNA were assessed in selected blastocysts by combining Hoechst 33342 and terminal dUTP nick‐end labelling (TUNEL) staining. Plasma concentrations of oestradiol (E2) and progesterone (P4) were determined by electrochemiluminescence from the day of FSH treatment, on the day of superovulatory oestrus and on the day before embryo collection. Compared with the control group, the does that received leptin had a higher number of transferable embryos (p < 0.005), fewer embryos classified as degenerated (p < 0.001) and fewer TUNEL‐positive cells/blastocyst (p < 0.001). The number of transferable embryos was positively correlated with E2 concentrations on day of oestrus (r = 0.562; p < 0.01) and P4 concentrations on the day of embryo collection (r = 0.912; p < 0.001). We concluded that in vivo leptin administration during FSH treatment improved embryo quality and affected ovarian steroidogenesis in superovulated goats.  相似文献   

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