共查询到20条相似文献，搜索用时 15 毫秒
1.
Shi Z Jin W Watanabe G Suzuki AK Takahashi S Taya K 《The Journal of reproduction and development》2004,50(6):605-611
In the present study, changes in localization of nerve growth factor (NGF) and its receptors, trkA and p75 in the ovary were investigated during the estrous cycle of the golden hamster. The effect of LH surge on changes in localization of NGF, trkA and p75 in the ovary was also investigated. NGF and its receptors trkA and p75 were localized in oocytes, granulosa cells and theca cells of various stages of follicles throughout the estrous cycle. NGF and its two receptors were also present in numerous interstitial cells and luteal cells. The number of interstitial cells staining positively for NGF and its two receptors was greater in ovaries of day 1 (day 1=day of ovulation) than the other days during the estrous cycle. Treatment with the antiserum against luteinizing hormone releasing hormone (LHRH-AS) at 1100 h on day 4 completely blocked ovulation. There were few positive reactions for NGF and its two receptors in interstitial cells 24 hr after LHRH-AS injection. The effect of LHRH-AS treatment was blocked by a single injection of 10 IU human chorionic gonadotropin. The distinct widespread distribution of NGF and its two receptors in the ovary of golden hamsters suggest that NGF may be an important growth factor for regulation of ovarian function. Furthermore, the LH surge may be an important factor for inducing production of NGF and its two receptors in interstitial cells of the cyclic golden hamster. 相似文献
2.
This experiment was conducted to determine the changes in secretion of LH, FSH, estrogen and progesterone during follicle maturation. Ovaries were recovered from 11 non-treated (control) gilts, three on day 13, four on day 16, and four on day 19 of the estrous cycle, and from four altrenogest-treated gilts on day 19. Altrenogest, a progesterone agonist, was fed at a dose of 20 mg once daily from days 13 to 18 to block spontaneous follicle maturation. Gilts were bled daily from day 12 until slaughter. For control gilts, the number of follicles/gilt 1-6 mm in diameter decreased (P less than .05) from 93.5 on day 13 to 21.5 on day 19, and the number of large (greater than 6 mm) follicles increased (P less than .05) from 5.3 to 13.2. Altrenogest treatment blocked loss of small follicles and growth of large follicles between days 13 and 19. Plasma progesterone decreased (P less than .001) between days 12 and 16 in both control and altrenogest-treated gilts. Plasma FSH decreased (P less than .05) between days 12 and 16 only in control gilts. Plasma LH was not significantly affected by day or altrenogest treatment. Plasma estrogen increased (P less than .05) between days 15 and 19 only in control gilts. These results indicate that 1) no increased LH secretion was detected in conjunction with emergence of ovulatory follicles, and 2) atresia of nonovulatory follicles was associated with decreased secretion of FSH. Both atresia and decreasing FSH secretion began before estrogen concentration increased in the systemic circulation. 相似文献
3.
Fifty crossbred gilts immunized against bovine serum albumin (BSA) or androstenedione conjugated to BSA (AD) were used in three experiments. Primary immunizations were given at 120 d of age and boosters at 148 and 176 d. Gilts were moved to pens containing four to five animals each and exposed to boars beginning at 180 d of age. Immunization against AD did not affect age at puberty, percentage of gilts exhibiting estrus or duration of first estrous cycle. Over the three experiments, ovulation rate was 24% greater for AD-immunized gilts than for controls, and the number of corpora lutea was related positively (r = .82) to the log of the antibody titer. Number of ovulations decreased as interval from booster immunization to onset of estrus increased. During diestrus of the first estrous cycle, gilts immunized against AD had more follicles 5 to 10 mm in diameter, more total ovarian follicles and more total ovarian structures (corpora lutea plus follicles) than controls. Immunization against AD increased the frequency of LH pulses on d 16 but not on d 17 or 18, of the estrous cycle. However, average serum concentrations of LH, FSH and estradiol from 5 d before until 2 d after expected estrus were not different between treatment groups. Concentrations of AD in follicles 4 to 6 and greater than 7 mm in diameter were greater in gilts immunized against AD. Mean serum progesterone was higher on d 9 and 12 after mating in AD immunized gilts than in controls. Immunization against AD had no effect on maintenance of pregnancy or embryo survival rate. 相似文献
4.
Twenty cyclic gilts were injected im with either saline (control) or 1,000 IU of human chorionic gonadotropin (hCG) on d 12 of the estrous cycle to determine the effects of hCG on follicular development and steroidogenesis. Blood was collected when gilts were sacrificed on d 13 or 16. Follicles were classified as medium (3 to 6 mm in diameter) or large (greater than 6 mm diameter), dissected from the ovary, measured and weighed. Pieces of follicle wall were incubated 3 h in Krebs Ringer bicarbonate buffer (KRB) on ice in an atmosphere of air or at 37 C in an atmosphere of 95% O2:5% CO2. Unconjugated estrogen and progesterone in blood plasma, follicular fluid and 10,000 X g supernatants of incubated follicular tissue homogenates were quantified by radioimmunoassay. On d 13 follicles on ovaries of control or hCG-injected gilts were less than or equal to 6 mm in diameter. On d 16, one of five control gilts had some large follicles, while all five hCG-treated gilts had large as well as medium follicles. On d 16 follicular fluid of large follicles from hCG-injected gilts contained twofold more estrogen and 40-fold more progesterone than medium follicles on the same ovaries. Tissue from large follicles of hCG-injected gilts produced more progesterone in vitro than did tissue from medium follicles (P less than .05), but estrogen production did not differ. On d 16 medium follicles from control or hCG-injected gilts were larger, contained more estrogen and less progesterone than those recovered on d 13 (P less than .01).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
5.
6.
Experiments were conducted to evaluate expression of the estrogen receptor (ER) alpha and ERbeta genes in the uterus and ovarian follicles of gilts treated with 5alpha-dihydrotestosterone (DHT) during the follicular phase of the estrous cycle. This DHT treatment has enhanced ovulation rate but decreased blastocyst survival in previous experiments. Gilts received daily i.m. injections of 10 mg of DHT from day 13 (day 0 = onset of estrus) to day 18 (experiment 1), or from day 13 to 16 (experiment 2) of the estrous cycle. Gilts that served as controls received vehicle. The ovaries and a portion of uterine horn were surgically removed 24 h after the last treatment. Administration of DHT from day 13 to 18 of the estrous cycle decreased uterine wet weight (tendency, P = 0.10), and the relative amounts (ratios to ribosomal protein L19) of endometrial mRNA for the estrogen-responsive gene complement component C3. Gilts receiving DHT had greater amounts of ERbeta mRNA in the endometrium than those treated with vehicle in both experiments, but DHT did not alter the overall amounts of endometrial ERalpha mRNA. Immunohistochemical (IHC) analysis demonstrated that DHT did not alter the relative amounts of ERalpha in the myometrium, glandular and luminal epithelia and endometrial subepithelial stroma. In the ovary, amounts of ERalpha and ERbeta mRNAs in surface walls of follicles > or =6 mm in diameter were not altered by DHT treatments, however, DHT treatment from day 13 to 16 decreased the amounts of immunoreactive ERalpha in the theca interna at the surface walls of day 17 follicles (experiment 2). The amounts of immunoreactive ERalpha were greater in the granulosa than in the theca interna, and within cell type, the amounts of ERalpha were greater at the surface than at the basal region of the follicles, with the exception of the theca interna in follicles evaluated on day 19 (experiment 1). Treatment of gilts with DHT during the follicular phase of the estrous cycle increased ERbeta mRNA in the endometrium and influenced the amounts of immunoreactive ERalpha in ovarian follicles in a cell type-, day of development- and region-specific manner. 相似文献
7.
Ren L Medan MS Weng Q Jin W Li C Watanabe G Taya K 《The Journal of reproduction and development》2005,51(3):399-404
The objective of this study was to determine the immunolocalization of NGF and its receptors (TrkA and p75LNGFR) in the reproductive tract of the Japanese Shiba goats. Five adult goats were used in this study and sections of ovaries, uteri and oviducts were immunostained by the avidin-biotin-peroxidase complex method (ABC). The results showed that NGF and its receptors (TrkA and p75LNGFR) were expressed in granulosa cells, theca cells, interstitial cells and lutein cells in ovaries. Immunoreactions for NGF, TrkA and p75LNGFR were also detectable in epithelial cells and muscle cells of the ampulla and isthmus of the oviduct, and in epithelial cells and uterine glands of the uterus. These results strongly suggest autocrine and paracrine regulation of reproductive function by NGF in the reproductive tract of female Shiba goats. 相似文献
8.
The effect of glucocorticoids on early follicular growth in sows undergoing normal estrous cycles was evaluated by administration of dexamethasone during the middle of the luteal phase. Plasma specimens were obtained for measurement of luteinizing hormone (LH), follicle-stimulating hormone (FSH), progesterone, and estradiol-17 beta concentrations. Fifteen sows were used. Control sows (n = 5) were given physiologic saline solution twice daily from day 9 to day 14 of the estrous cycle. Sows of the second group (n = 5) were given dexamethasone (30 micrograms/kg of body weight, IM) similarly, and those of the third group (n = 5) were given dexamethasone plus gonadotropin-releasing hormone (GnRH; 50 micrograms at 6-hour intervals, IV). Plasma specimens, obtained twice daily from day 8 through day 26, indicated that progesterone production and luteal regression were not inhibited by any of the 3 treatment regimens. Although preovulatory plasma estradiol concentration increased in control sows, such was not observed in the sows treated with dexamethasone or dexamethasone plus GnRH (P less than 0.01). Ovulation, with formation of corpora lutea, occurred in gilts given saline solution. Dexamethasone administration resulted in persistence of 19 to 41 follicles/ovary (2 to 4 mm in diameter), and dexamethasone-plus-GnRH treatment resulted in 6 to 18 follicles/ovary (5 to 6 mm in diameter). Plasma was obtained at 15-minute intervals for 12 hours to compare the effect of treatment on hormone concentrations on day 12 of the estrous cycle with the values on day 8.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
9.
Seventy-one 10th-generation gilts from White Line-1 (WL-1 = randomly selected control line) and White Line-2 (WL-2 = selected for an index of ovulation rate and prenatal survival rate) were used to compare the pattern of follicular development and atresia during the follicular phase of the estrous cycle. Gilts were treated with PGF(2alpha)on d 13 of the estrous cycle (d 0 of induced follicular development) to induce luteolysis and assigned randomly within line and sire for ovary recovery on d 0, 2, 3, 4, 5, and the day after estrus. Ovaries were evaluated for numbers of corpora albicantia and small (2 to 2.9 mm), medium (M1 = 3 to 4.9 mm; M2 = 5 to 6.9 mm), and large (>or=7 mm) follicles. The concentration of estradiol-17beta in follicular fluid was used to classify individual M2 and large follicles as estrogen-active (>or=100 ng of estradiol-17beta/mL) or inactive (<100 ng of estradiol-17beta/mL). The WL-2 gilts had a greater ovulation rate than WL-1 gilts at their pre-treatment estrus (20.4 vs. 13.8 corpora albicantia; P < 0.001). The small and M1 follicle populations decreased rapidly in both lines over time (P < 0.001). The M2 follicle population increased in both lines between d 0 to 4 and then decreased. Mean estradiol concentration of M2 follicles increased in both genetic lines over time (P < 0.02). All large follicles were estrogen-active in both lines; the number of large follicles increased with day (P < 0.001) and was similar in both lines. The number of estrogen-active M2 follicles was similar in both lines, increasing to d 3 and 4 and then decreasing (P < 0.01) thereafter. However, the total number of estrogen-active follicles (sum of estrogen-active M2 and large follicles) was greater in WL-2 than in WL-1 gilts (P < 0.04), increasing to the ovulatory potential by d 3 in WL-1 gilts, but continuing to increase through d 4 in WL-2 gilts. Selection of an additional six ovulatory follicles from the estrogen-active M2 follicle pool after d 5 was required in both lines to achieve the projected ovulation rate, and after estrus, the number of large follicles remained insufficient to attain the ovulatory potential of each line. 相似文献
10.
Weng Q Shi Z Kawaguchi M Watanabe G Taya K 《The Journal of reproduction and development》2008,54(5):397-401
Characteristic daily increases in the plasma levels of luteinizing hormone (LH) are present every afternoon during lactation in golden hamsters. The objective of this study was to investigate the effect of the diurnal rhythm of increases in LH on expression of nerve growth factor (NGF), its receptors trkA and p75 and inhibin alpha-subunit in the ovarian interstitial cells of lactating golden hamsters. Both lactating and non-lactating groups of postpartum golden hamsters were used in this study. The expression of NGF, its receptors trkA and p75 and inhibin alpha-subunit were determined by immunohistochemistry. Positive staining of NGF, trkA and p75 was found in the interstitial cells of the lactating group, and no immunoreactivity for NGF, trkA or p75 was observed in the ovarian interstitial cells of the non-lactating group. In addition, immunostaining of inhibin alpha-subunit was also observed in the interstitial cells of the lactating group but not in those of the non-lactating group. Immunostaining of the inhibin/activin beta(A)- and beta(B)-subunits was observed in the granulosa cells of antral follicles, but not in the interstitial cells of the lactating and non-lactating animals. These results suggest that the diurnal rhythm increases in LH can induce expression of NGF, trkA, p75 and inhibin alpha-subunit in the ovarian interstitial cells of lactating golden hamsters and that NGF, its receptors trkA and p75 and inhibin alpha-subunit may have the capacity for autocrine or paracrine modulation of interstitial cell differentiation in golden hamsters. 相似文献
11.
The objectives of this study were to characterize and compare ovarian follicular populations in Gene Pool Control (GPC, randomly selected) and Relax Select line (RS, nine generations of selection for high ovulation rate followed by six generations of random selection) gilts during different stages of the estrous cycle. Thirty-five RS and 23 GPC gilts were allotted randomly within litter for ovary recovery on either d 3, 15 or 19 of the estrous cycle. Surface follicles on the ovaries were classified by size (small, less than 3 mm; medium, 3 to 6.9 mm; large, 7 to 12 mm), and counts were recorded for each ovary. Ovarian weight (OW), number of corpora lutea (CL), follicular fluid volume (FFV) from small, medium and large follicles, residual ovarian weight and follicular fluid weight (FFW) also were recorded. Total numbers of small and medium follicles were greatest on d 15, whereas total number of large follicles and FFW were greatest on d 19. The OW, FFW and follicle numbers of all classes were lowest on d 3. The RS gilts expressed longer interestrous intervals (21.9 vs 20.4 d, P less than .05) and higher ovulation rates (18.5 vs 15.3 CL, P less than .01) than GPC gilts. The left ovary of RS gilts was responsible for most of the ovulation rate advantage (10.3 vs 7.4 CL, P less than .01) Overall, GPC gilts had more total small follicles than RS gilts (P less than .01). The advantage was due primarily to higher numbers of small follicles at d 15.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
12.
The present study was designed to examine the influence of gonadotrophins treatment on the ovarian morphology changes and plasma concentrations of steroid hormones in peripheral blood. The experiment was performed on sexually pubertal gilts (Large White x Landrace) of similar age (7-8 months) and body mass (100-110 kg) with two controlled subsequent estrous cycles. The animals were randomly divided into four groups: two control consisting of pigs with the luteal phase (n = 9, the 10th day of the estrous cycle) and the follicular phase (n = 6, the 20th day of the estrous cycle) and two experimental ones consisting of animals with both mentioned periods (n = 7 and n = 9) treated with gonadotrophins (PMSG and hCG). The gilts in the luteal phase were injected (s.c.) with gonadotrophins at a daily dose of PMSG 400 and hCG 200 IU from the 16th to the 27th day (the 6th day of the next estrous cycle). The gilts in the follicular phase, were injected with the same dose of gonadotrophins but from the 8th to the 19th day of the estrous cycle. Plasma concentrations of P4, A4, T, E1, E2 and metabolite of PGF2 alpha-PGFM were determined by radioimmunoassay (RIA) method. Injections of PMSG and hCG in both experimental groups produced several times enlarged: weight, size and volume of ovaries and alterations in a number of structural elements as compared with those found in the control animals. The morphological elements presented in ovaries: corpora haemorrhagica, corpora lutea, regular and atretic follicles and first of all cysts by distinctly differentiation thickness of the walls are characteristic for cystic ovarian degeneration. Plasma concentrations all determined hormones after gonadotrophins treatment in experimental groups were increased except E1 (insignificant decrease) in luteal phase as compared with those found in the control groups. Statistically significant increase (p < 0.001) in plasma concentrations of P4, A4, and T in both experimental groups and E2 (p < 0.001) in luteal phase were noted. In peripheral plasma concentrations increase of E1 and E2 in follicular phase of the estrous cycle were insignificant. 相似文献
13.
Sixteen crossbred heifers were assigned at random on d 3 of an estrous cycle to continue to receive the medium quality hay (control diet) or to be flushed with a grain ration (high-energy diet) until slaughtered on d 12 or 16. The ovarian follicles were counted and measured using routine histological techniques. Both the nonatretic and atretic (more than four pyknotic bodies) antral follicles (greater than .14 mm) were separated into six classes according to diameter size. The mean number of nonatretic follicles measuring .29 to .67 mm and .68 to 1.57 mm in heifers on a high-energy diet increased from 30.8 and 8.1 on d 12 to 57.5 and 15.5 on d 16, whereas in heifers on a control diet it decreased from 43.1 and 13.0 to 28.1 and 6.5, respectively (energy in diet X day of estrous cycle interaction, P less than .05). The mean number of nonatretic follicles measuring 3.68 to 8.56 mm decreased from 2.1 to 0 between d 12 and 16 in heifers on a high-energy diet while it remained the same at 0 and .5, respectively, for heifers on a control diet (energy in diet X day of cycle interaction, P less than .05). Of the total number of follicles (mean = 161) 38.2% were atretic. Mean number of atretic follicles measuring 1.58 to 3.67 mm in heifers on a high-energy diet increased from 14.8 at d 12 to 31.0 at d 16 whereas in heifers on a control diet it decreased from 27.4 to 13.3, respectively (energy in diet X day of cycle interaction, P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
14.
Studies in cattle assessing changes in number and size of antral follicles, concentrations of estradiol, androgens and progesterone in serum and follicular fluid, and numbers of gonadotropin receptors per follicle during repetitive estrous cycles and postpartum anestrus are reviewed. The rate of growth of small follicles (1 to 3 mm) into larger follicles increases as the estrous cycle progresses from d 1 to 18 (d 0 = estrus). Size of the largest antral follicle present on the ovary also increases with advancement of the estrous cycle. Most large follicles (greater than 10 mm) persist on the ovarian surface for 5 d or more between d 3 and 13 of the bovine estrous cycle. After d 13, most of these large follicles are replaced more frequently by new growing follicles (turnover) with an increased probability for recruitment of the ovulatory follicle after d 18. More research is needed to determine the time required for growth of bovine follicles from small to large antral size and evoke recruitment of the ovulatory follicle. Factors that regulate selection of the ovulatory follicle are unknown but may involve increased frequency of LH pulses in blood, altered blood flow and(or) changes in intrafollicular steroids and proteins. Quantitative evaluation of ovarian follicles indicated occurrence of consistent short-term changes in fluid estradiol and numbers of luteinizing hormone receptors in cells of large follicles only during the pre-ovulatory period. Presumably, low concentrations of follicular estradiol found during most of the estrous cycle are not due to a lack of aromatizable precursor or follicle-stimulating hormone receptors. Follicular fluid concentrations of progesterone increase only near the time of ovulation. Little is known about changes in follicular growth, turnover and function during postpartum anestrus in cattle. However, preliminary data suggest that the steroidogenic capacity of large follicles changes markedly during the postpartum period. 相似文献
15.
A. Shirazi PhD F. Gharagozloo PhD A. Niasari-Naslaji PhD M. Bolourchi PhD 《Journal of Equine Veterinary Science》2002,22(5)
The characteristics of the major follicular waves (primary and secondary) throughout estrous cycle were studied in 7 healthy Caspian mares (age, 4-15 years; weight, 198.6 ± 0.9 kg) during the breeding season. Ovarian follicular dynamics were monitored by using an ultrasound scanner equipped with a 5-MHz, B-mode, linear-array, rectal transducer throughout 2 complete estrous cycles. The diameters of antral follicles (5 mm) were measured, averaging the narrowest and widest dimensions. To detect follicular wave emergence, the diameter profile of the 3 largest follicles per ovary of each mare was determined without considering day-to-day identity of follicles but with maintenance of distinction between left and right ovaries. The primary waves originated on day 6.4 ± 0.81 (ovulation = day 0) when the mean diameter of ovarian follicles was 9.6 ± 1.05 mm. Divergence between the dominant preovulatory follicle and subordinate follicles occurred on day 13.4 ± 0.81, when the dominant follicle was 18.1 ± 2.67 mm in diameter. The intervals from emergence to divergence and from divergence to ovulation were 7 ± 0.68 and 8.7 ± 0.68 days, respectively. Secondary major follicular waves were not observed during this study. In conclusion, only 1 major follicular wave was detected in a Caspian mare, confirming the data previously described in other equine breeds. It is also indicated that the occurrence of 1 major follicular wave per cycle is a more common phenomena in equine species. 相似文献
16.
Until 1999 it was accepted that pheromones act exclusively by stimulating the dendritic receptors present in olfactory epithelium. Cycling gilts with an experimentally-disrupted neural olfactory pathway were used to test the hypothesis that boar pheromone 5alpha-androstenol may affect the secretion of hormones involved in the regulation of the estrous cycle by the humoral pathway. On day 12 of the estrous cycle the nasal cavity of gilts (n=15) was irrigated with zink sulfate solution. From day 16 to 20, the experimental group (n=10) was injected intramuscularly with 5alpha-androstenol (20 microg) twice a day. Blood samples were collected from the jugular vein at 4 h intervals on days 17-21 to estimate plasma concentration of LH, oxytocin, estradiol-17beta, testosterone and progesterone. The experimental group displayed a significantly lower mean concentration of LH than the control animals (P<0.0001). The decrease in concentration of LH was accompanied by the reduction of oxytocin (P<0.001), estradiol-17beta (P<0.001) and testosterone (P<0.01) secretion. These results demonstrated that 5alpha-androstenol influenced hormonal regulation by humoral pathway and might be considered to be the priming pheromone in gilts. 相似文献
17.
In this study we measured protein concentrations of insulin-like growth factor (IGF)-I and IGF binding proteins (IGFBPs) 2-5 in porcine corpora lutea (CLs) throughout the estrous cycle (Experiment 1), and examined the effects of IGFBP-3 and IGFBP-3 antibody (AB) on luteal progesterone (P4) secretion in vitro (Experiment 2). For Experiment 1, (CLs) and serum were collected on days (D) 4, 7, 10, 13, 15 and 16 of the estrous cycle (n = 5 animals per day). IGF-I was extracted from CLs and sera, and measured by radioimmunoassay (RIA). IGFBPs were measured in CLs by ligand blots. For Experiment 2, CLs (from Experiment 1) were enzyme dissociated and luteal cells cultured (24 h) in Medium 199 (M199) containing (0-500 ng/ml) IGFBP-3 (+/-IGF-I; 100 ng/ml), or (0-10 microg/ml) IGFBP-3 AB. P4 in media was measured by RIA. In Experiment 1, luteal IGF-I concentrations (ng/g tissue) were maximal on day 4 and gradually decreased thereafter. Serum IGF-I concentrations (ng/ml) were highest on days 4 and 7, compared with days 10-15. Peak levels of luteal IGFBP-3 were also seen on days 4 and 7 of the cycle. Luteal IGFBP-2 concentrations showed a tendency to increase on day 16 (P < 0.05 versus day 10), but no significant changes in IGFBP-4 or -5 were seen. In Experiment 2, IGFBP-3 (w IGF) inhibited the steroidogenic actions of IGF-I, but had no significant actions alone (IGFBP-3 w/o IGF). Finally, IGFBP-3 AB stimulated P4 secretion on days 4 and 7, but not on days 10-16. We conclude that IGFBP-3 inhibits IGF-I actions in the porcine CL. 相似文献
18.
Koji Misumi Yuri Hirayama Misae Suzuki Michiko Nakai Junko Noguchi Hiroyuki Kaneko Kazuhiro Kikuchi 《Animal Science Journal》2014,85(2):112-117
Collection efficacy and in vitro embryo developmental ability of oocytes obtained from Duroc‐breed ovary donors at different stages of the estrous cycle (days 6, 12 and 16 after estrus) were performed. The numbers of collected oocytes did not differ significantly among the different estrous cycle groups (total 72–90 oocytes per gilt). However, the blastocyst rates of oocytes collected on days 12 and 16 (9.2% and 19.4%, respectively) were significantly higher than those on day 6 (1.1%). More oocytes were obtained on day 16 from small follicles (<2 mm in diameter; 85.3 oocytes per gilt) than from medium‐sized (≥2–<6 mm) and large (≥6 mm) follicles (17.5 and 12.8 oocytes, respectively). The blastocyst rates in both the medium‐sized and large follicle groups (20.0% and 19.2%, respectively) were significantly higher than that in the small follicle group (6.3%). The blastocyst cell numbers in both the medium‐sized and large follicle groups (39.4 and 43.3 cells, respectively) were significantly higher than that in the small follicle group (30.6 cells). The results suggest that oocyte collection from cycling Duroc pigs can be carried out efficiently from the late luteal to follicular stage. Those oocytes collected from medium‐sized and large follicles show better embryo development. 相似文献
19.
Galeati G Forni M Govoni N Spinaci M Zannoni A De Ambrogi M Volpe S Seren E Tamanini C 《Domestic animal endocrinology》2007,33(3):281-293
The aims of this study were to study the effects of fasting on progesterone (P4) production in the pig and to verify whether fasting influences luteal expression of PGF(2alpha) receptor (FPr) and prostaglandin secretion. Superovulated prepubertal gilts were used; half of them were fasted for 72h starting on day 2 (F2) or 9 (F9) of the induced estrous cycle, respectively, while two groups (C2 and C9) served as respective controls. Plasma P4 and PGFM concentrations were determined by RIA while FPr mRNA expression in CLs collected at the end of fasting period was measured by real-time PCR. In experiment 1, plasma P4 concentrations in fasted gilts were significantly (P<0.01) higher than in controls starting from day 3 (F2; n=6) and 10 (F9; n=6). FPr mRNA expression was similar in F2 and C2 (n=6) CLs while it was significantly (P<0.05) higher in F9 than in C9 (n=6) CLs. In experiment 2, cloprostenol administered on day 12 significantly (P<0.05) increased FPr mRNA expression in CLs from both F9 (n=6) and C9 (n=6) gilts. At the time of cloprostenol injection PGFM levels were significantly higher (P<0.05) in the fasted group and cloprostenol-induced luteolysis in fasted but not in normally fed gilts. Results from this study indicate that fasting in prepubertal gilts induced to ovulate stimulates luteal P4 and PGFM production as well as FPr mRNA expression, thus increasing luteolytic susceptibility. 相似文献
20.
T Wise 《Journal of animal science》1987,64(4):1153-1169
To investigate some biochemical changes during bovine follicle development, ovaries were obtained from cyclic heifers (7 to 11 heifers/d on each day of the 21-d estrous cycle; N = 152). Follicular fluid from the two largest follicles from both ovaries and a pool from small follicles (N = 30/cow) were collected from each animal and analyzed for ionic, enzymatic and endocrine changes in relation to day of the estrous cycle, follicle size, rank and atretic or growing status. Follicular fluid alkaline phosphatase activity and ascorbate concentrations were highest in all follicular sizes during the earlier portion of the estrous cycle (d 1 to 12; P less than .05), then decreased to the lowest levels (d 13 to 21). As follicular size (diameter) increased lactate dehydrogenase (LDH), acid and alkaline phosphatase activity was reduced in follicular fluid (P less than .05). Alkaline phosphatase and LDH activity tended to be increased in atretic follicles (P less than .10), and was correlated with increased progesterone and androgen concentrations of follicular fluid (r = .4, P less than .05). Both albumin and total protein concentrations decreased as follicular diameter increased (P less than .05). Sodium concentrations in follicular fluid were greater in growing-antral than atretic follicles, and increased with follicular enlargement (P less than .05). Follicular potassium concentrations increased as the estrous cycle progressed (P less than .05), and tended to be elevated in atretic follicles (nonsignificant). Both Ca and Mg concentrations increased with follicular enlargement (P less than .05). Dehydroepiandrosterone and testosterone were the predominant androgens in follicular fluid (androstenedione, the lowest concentration); their concentration decreased with follicle development (P less than .05), but were quite variable. Estradiol was increased in growing follicles (P less than .01). Estrone and estradiol concentrations increased as ovulation approached, particularly in small follicles (less than or equal to 4 mm diameter). Changes of biochemical components found in follicular fluid that relate to the growth and atresia process may provide a more sensitive and accurate method to classify follicle status, and thus aid in understanding the complexity of events associated with maturation of the bovine follicle and oocyte. 相似文献