Electroacupuncture facilitates implantation by enhancing endometrial angiogenesis in a rat model of ovarian hyperstimulation.

Controlled ovarian hyperstimulation (COH) impairs the synchronized development of endometrium and embryo, resulting in the failure of embryo implantation. Here, we investigated what effects electroacupuncture had on embryo implantation in COH rats. Female rats were randomly assigned to four groups: normal (N), model (M), electroacupuncture (EA), and electroacupuncture pretreatment (PEA). Rats in groups M, EA, PEA were injected with pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin to establish the COH model. Rats in group EA received electroacupuncture treatment from the PMSG injection day to the 3rd day of pregnancy (D3), while those in group PEA received electroacupuncture treatment for 3 days before the PMSG day and continuing to D3. Furthermore, another 30 female rats who received the same treatment as the rats in group PEA were injected with siVEGFR2 into uterine lumen. The endometrial microvascular density (MVD) and the expression levels of vascular endothelial growth factor-A, angiopoietin-1, and fibroblast growth factor-2 were significantly lower in groups M than in groups N and PEA. The percentage of dolichos biflorus agglutinin positive uterine natural killer cells in groups N, EA and PEA was higher than that in group M. After the siVEGFR2 injection, the protein expression levels of vascular endothelial growth factor receptor 2 (VEGFR2), PI3K, p-AKT and p-ERK, the embryo number and the MVD were significantly reduced. In conclusion, electroacupuncture can facilitate embryo implantation in COH rats by activating the VEGFR2/PI3K/AKT and VEGFR2/ERK signaling pathways which have a positive relationship with endometrial angiogenesis.

Luteal P4 synthesis in early pregnant gilts after induction of estrus with PMSG/hCG.

The present study was designed to examine whether an estrus induction with gonadotropins could affect luteal P4 synthesis in early pregnant gilts. Sixteen prepubertal gilts received 750IU of PMSG and 500IU of hCG 72h later. Prepubertal gilts in the control group (n=17) were observed daily for estrus behavior. All gilts were inseminated in their first estrus. Corpora lutea (CLs) were collected on days 10, 12 and 15 of pregnancy and analyzed for (1) the mRNA and protein expression of steroidogenic acute regulatory protein (StAR), cytochrome P450 family 11 subfamily A polypeptide 1 (CYP11A1), and 3ß-hydroxysteroid dehydrogenase (3ßHSD); (2) the tissue concentration of P4; and (3) the mRNA expression of luteinizing hormone receptor (LHR) and estrogen receptors (ESR1 and ESR2). Additionally, P4 concentration was analyzed in blood serum of all animals. PMSG/hCG injections to induce estrus decreased mRNA expression of StAR, CYP11A1 and 3ßHSD on day 10 and CYP11A1 on day 12 of pregnancy compared with the control group, while CYP11A1 and 3ßHSD proteins were down-regulated on day 10 in the hormonally-treated gilts. Concentrations of P4 in luteal tissue and blood serum were also lower in animals after gonadotropin-induced estrus. In contrast, LHR and ESR1 mRNA expression was greater in PMSG/hCG-treated than control gilts on day 15 of gestation. In conclusion, induction of estrus with a PMSG/hCG protocol in prepubertal gilts impaired expression of the luteal P4 synthesis system. Low P4 content may, in turn, induce local mechanisms involving LHR and ESR1 expression to support CL function.

Gonadotropin stimulation using P.G. 600® on reproductive success of non-lactating anestrous ewes.

The effect of stimulation with a gonadotropin preparation with combined follicle stimulating and luteininzing hormone like activity on reproductive success in anestrous ewes was evaluated. In Experiment 1, ewes of mixed breeding were treated with CIDR inserts (0.3g progesterone) for 5 days and were assigned randomly to receive either gonadotropin stimulation (3mL i.m. injection of P.G. 600®, 240IU eCG and 120IU hCG) at CIDR removal or no further treatment. Intact raddled rams were joined at insert removal for 30-35 days, and ewes were observed for indications of estrus after 4 days of ram exposure. Pregnancy diagnosis was conducted via transrectal ultrasonography at the time of ram removal and again 20-25 days. The second experiment was similar to Experiment 1, except treated ewes received the gonadotropin 1 day prior to insert removal. In Experiment 1, incidence of estrus was greater for treated ewes (P=0.01), and prolificacy tended to be greater in treated ewes (P=0.06). In Experiment 2, treated ewes had greater conception rates (P=0.01), pregnancy rates to first service (P=0.0007), and tended to have greater overall pregnancy rates than control ewes (P=0.07). A greater percentage of ewes lambed in the gonadotropin treated ewes than in ewes in the control group (P<0.0001), and overall lambing rates in treated ewes were greater than non-treated controls (P<0.0001). In conclusion, gonadotropin treatment 1 day prior to CIDR removal increased reproductive success in progesterone-treated anestrous ewes.

Resynchronization of estrous cycle with eCG and temporary calf removal in lactating Bos indicus cows.

The aim of this study was to compare four methods of estrus resynchronization performed 23 days after timed artificial insemination (TAI) plus estrus observation in Bos indicus cows. Eight hundred fourteen lactating Nelore cows were submitted to TAI and then randomly assigned to one of the five following treatments: R23 (resynchronization without eCG), R23/200 (resynchronization with 200 IU of eCG), R23/300 (resynchronization with 300 IU of eCG), R23/TCR (resynchronization with temporary calf removal [TCR]), and a control group, with estrus observation followed by AI (with no resynchronization). Treatment consisted of a progesterone device plus administration of estradiol benzoate on Day 0; on Day 8, the device was removed and cloprostenol was applied, together with estradiol cypionate. Also on Day 8, either eCG was administered or TCR was performed in the resynchronized groups, except for R23. The females were inseminated 48 hours after device removal or TCR (33 days after the first TAI). The control group was kept under estrus observation from 18 to 23 days after the first TAI and was inseminated 12 hours after detection of estrus. The first pregnancy evaluation was performed using ultrasound examination 31 days after the first TAI. After 30 days of the resynchronization, a second pregnancy evaluation was performed and the animals in the R23/300 and R23/TCR groups achieved the highest conception rates, 76.6% and 74.0%, respectively (P < 0.05). There were no differences between the conception rates of the animals in the R23/200 (63.3%), R23 (61.3%), and control (54.3%) groups (P > 0.05). These results suggest that estrus resynchronization at 23 days after TAI can effectively improve the conception rate of lactating Bos indicus cows in a short time period. Furthermore, resynchronization with 300 IU of eCG or with TCR provided the best results.

Hormone replacement therapy in children with hypogonadotropic hypogonadism: where do we stand?

OBJECTIVE: To characterize hormone replacement therapy in a cohort of adolescent males and females with hypogonadotropic hypogonadism (HH) with a focus on changes in management during the past 10 years. METHODS: Medical records of patients followed for HH during the past 10 years were reviewed. RESULTS: A total of 45 patients (22 female: 23 male) with HH were identified. The average age at HH diagnosis was 14.48 ± 2.02 years in females and 14.89 ± 1.64 years in males (P = .53). In females, the average age of pubertal induction was 14.53 ± 1.86 years. Conjugated equine estrogen was used in 54.5%, transdermal estradiol in 41%, and oral estradiol in 4.5%. The average duration to cycling was 1.96 ± 0.78 years. A progressive increase in the use of transdermal estradiol was noted over time, with 100% of females being started on this regimen since 2008. In males, the average age of induction was 15.22 ± 1.41 years. All were started on intramuscular testosterone cypionate at various doses. The average duration to full adult replacement was 1.95 ± 0.51 years. CONCLUSION: There is no current standard of care to guide pubertal induction in adolescents with HH. However, a significant increase in the use of transdermal estrogen was noted in females during the past 10 years. While much less variability in pubertal induction was seen in males, wide disparities in doses and escalation schedules were found. Prospective studies aimed at elucidating optimal strategies for sex steroid replacement in this pediatric population are badly needed.

Ovarian reaction and estrus manifestation in delayed puberty gilts after treatment with equine chorionic gonadotropin.

BACKGROUND: Prolonged pre-insemination anestrus (i.e. delayed puberty) is a major contributing factor for culling up to 30% of the replacement gilts at large breeding farm units in Vojvodina. It is imperative to determine if these gilts are acyclic (prepubertal) or cyclic, but just fail to exhibit behavioural estrus. Recent investigations demonstrate that treatment with equine chorionic gonadotropin (eCG) can increase the diestrous phase duration in sexually mature gilts. Based on these finding, the aim of the present studies was to determine the reproductive status of delayed puberty gilts following injection with eCG. METHODS: Two experiments were conducted on a swine breeding farm in Vojvodina. In Exp. 1, 20 prepubertal (acyclic) gilts, and 120 sexually mature (cyclic) gilts were injected with a single injection of 400 IU eCG + 200 IU human chorionic gonadotropin (hCG) or with 1000 IU eCG (cyclic gilts), at d5, d11 or d17 after spontaneous estrus detection, to determine their ovarian reaction and induced estrus manifestation. In Exp. 2, sixty delayed puberty gilts (estrus not detected until 8 month of age, av. 258 days) were culled from breeding herd and slaughtered to determine their reproductive status based on ovarian anatomical features. The second group of gilts (n = 60) was treated with a single 1000 IU eCG injection to determine their reproductive status, based on the interval between eCG injection to estrus detection and duration. The data were analyzed by descriptive statistics, t-test, analysis of variance and Duncan's test in the software package Statistics 10th. RESULTS: Ovulations were induced in 90% of acyclic (sexually immature) and, on average, 93.3% of cyclic (sexually mature) gilts after the eCG injection. On average, 4 days after the eCG injection, estrus was detected in 85% of the treated acyclic (sexually immature) gilts and in 95% (19/20) of the cyclic (sexually mature) gilts, treated with eCG on day 17 after spontaneous estrus detection. The interval from eCG to induced estrus detection was prolonged (av. 25 days) in 95% (19/20) of the sexually mature gilts treated with eCG on day 5 and in 90% (18/20) of gilts treated on day 11 after spontaneous estrus detection (Exp. 1). Forty anestrous gilts reached cyclic pubertal ovarian activity. Estrus manifestation was detected in 56 gilts (93.3% of the total 60 treated prolonged anestrous gilts, av. 259 days of age), after a single 1000 IU eCG injection. Thirty-four gilts (60.7% of the total gilts in estrus) with prolonged eCG to estrus interval (av. 24.7 days) were considered spontaneously cyclic (sexually mature), but behaviourally anestrous before treatment. The remaining 22 (39.3% of the total gilts in estrus) were considered truly sexually immature (acyclic) before the treatment or were eCG injected in the late luteal or proestrous phase of spontaneous estrous cycle (Exp. 2). CONCLUSIONS: In 66.7% of the delayed puberty gilts, pre-ovulatory follicles (PoF), corpora hemorrhagica (CH), corpora lutea (CL), or corpora albicantia (CA) were found on the ovaries upon post mortem examination. These gilts were considered as sexually mature before slaughtering. In 60.7% of the delayed puberty gilts, behavioural estrus was detected an average of 24.7 days following eCG injections. These gilts were considered as eCG treated during the luteal phase (diestrus) of the spontaneous estrus cycle. Both findings suggest that delayed puberty gilts actually reached cyclic pubertal ovarian activity (sexual maturity) before culling from the breeding herd.

Progesterone concentrations, exogenous equine chorionic gonadotropin, and timing of prostaglandin F(2alpha) treatment affect fertility in postpuberal Nelore heifers.

Two experiments were performed to test the hypothesis that elevated progesterone concentrations impair pregnancy rate to timed artificial insemination (TAI) in postpuberal Nelore heifers. In Experiment 1, postpuberal Nelore heifers (n=398) received 2mg estradiol benzoate (EB) and either a new progesterone-releasing intravaginal device containing 1.9g of progesterone (CIDR) (first use) or a CIDR previously used for 9 d (second use) or for 18 d (third use) on Day 0, 12.5mg prostaglandin F(2alpha) (PGF(2alpha)) on Day 7, 0.5mg estradiol cypionate (ECP) and CIDR withdrawal on Day 9, and TAI on Day 11. Largest ovarian follicle diameter was determined on Day 11. The third-use CIDR treatment increased largest ovarian follicle diameter and pregnancy rate. Conception to TAI was reduced in heifers with smaller follicles in the first- and second-use CIDR treatments, but not in the third-use CIDR treatment. In Experiment 2, postpuberal Nelore heifers received the synchronization treatment described in Experiment 1 or received 12.5mg PGF(2alpha) on Day 9 rather than Day 7. In addition, 50% of heifers received 300 IU equine chorionic gonadotropin (eCG) on Day 9. Heifers were either TAI (Experiment 2a; n=199) or AI after detection of estrus (Experiment 2b; n=125 of 202). In Experiment 2a, treatment with eCG increased pregnancy rate to TAI in heifers that received PGF(2alpha) on Day 9 but not on Day 7 and in heifers that received a first-use CIDR but not in heifers that received a third-use CIDR. Treatments did not influence reproductive performance in Experiment 2b. In summary, pregnancy rate to TAI in postpuberal Nelore heifers was optimized when lower concentrations of exogenous progesterone were administered, and eCG treatment was beneficial in heifers expected to have greater progesterone concentrations.

The efficacy of recombinant equine follicle stimulating hormone (reFSH) to promote follicular growth in mares using a follicular suppression model.

The efficacy of a recently engineered single chain recombinant equine follicle stimulating hormone (reFSH) was investigated in estrous cycling mares whose gonadotropins and follicular activity had been suppressed by concurrent treatment with progesterone and estradiol (P&E). Time of estrus was synchronized in 15 estrous cycling mares during the breeding season with prostaglandins F(2alpha) (PGF(2alpha)). The day after ovulation, mares were treated once daily with P&E for 14 days. Mares received a second injection of PGF(2alpha) on day 6 of the synchronized estrous cycle to induce luteolysis. On day 8 post-ovulation mares were randomly assigned to three groups: small dose reFSH-treatment group (0.5mg reFSH IV, twice daily); large dose reFSH-treatment group (0.85mg reFSH IV twice daily); control group (saline IV, twice daily). reFSH treatment occurred concurrently with the last week of P&E treatment. After a follicle or cohort of follicles reached 35mm in diameter, mares were injected with 0.75mg of recombinant equine luteinizing hormone (reLH) to induce ovulation. Post-treatment ovulation was assessed. Daily blood samples were collected for analysis of FSH, LH, estradiol, progesterone, and inhibin by radioimmunoassay (RIA). On the first day of reFSH/saline treatment, blood samples were collected periodically from 1h prior to treatment to 6h post-injection via an indwelling jugular catheter to determine acute changes in FSH concentrations. Monitoring of follicular activity, estrus, and ovulation was performed daily by utilizing a stallion and transrectal ultrasonography. A difference (por=35mm follicles (days 16-21) than controls. Mares treated with reFSH, at either dose, took less time (average: 2.95+/-0.42 days) to develop 2-3 times more pre-ovulatory follicles than control mares (7.8+/-0.51 days) (p

GnRH or eCG treatment fails to restore reproductive function in GnRH immunized ewes.

This study was designed to evaluate the potential of using eCG or GnRH in restoring reproductive functions in GnRH immunized ewes. Thirty-three multiparous Kivircik ewes were randomly assigned into either control group (n=11) or immunization group (n=22). Ewes were immunized against GnRH by injecting with a cocktail of ovalbumin-LHRH-7 (ovalbumin-GnRH-7) and thioredoxin-LHRH-7 (thioredoxin-GnRH-7) fusion proteins generated by recombinant DNA technology in April. 500 IU eCG or 0.008 mg GnRH analogue was used to induce ovulations. Serum GnRH antibodies were present in animals of the immunized group beginning the second week after the first immunization and maintained throughout the study (14 months). Immunization caused anestrus in immunized ewes. eCG or GnRH analogue administration given after 14 days progestagen (20 mg fluorogestone acetate, FGA) treatment during breeding season (mid July) did not induce ovulation in these ewes. Two more attempts with single or multiple eCG injections failed to induce ovulation in this group as well. It appears that the gonadotropin stimulation was not of adequate time since neither eCG nor GnRH administration was able to restore reproductive function in immunized animals. The immunization effect lasted more than a year. These results suggest that GnRH immunization exerts its effect via the hypothalamo-pituitary axis and that more than such stimulation is required to overcome the reproductive suppression.

Relationships between ovarian blood flow and ovarian response to eCG-treatment of dairy cows.

The goal of the present study was to investigate ovarian blood flow and ovarian response in cows undergoing a gonadotropin treatment to induce a superovulatory response, using transrectal colour Doppler sonography. Forty-two cows including 19 cross-bred, 14 German Holstein and 9 German Black Pied cows were examined sonographically before hormonal stimulation on Day 10 of the oestrous cycle, three days after administration of eCG (Day 13) and seven days after artificial insemination (Day 7(p.i.)). After each Doppler examination, blood was collected for determination of total oestrogens (E) and progesterone (P4) in peripheral plasma. The blood flow volume (BFV) and pulsatility index (PI), which is a measure for blood flow resistance, were determined in the ovarian artery, and B-mode sonography was used to count dominant follicles and corpora lutea. Important criteria to assess the ovarian response following the hormonal treatment were the number of follicles >5mm in diameter on Day 13 and the number of corpora lutea on Day 7(p.i.) per cow. The number of follicles ranged from 2 to 61 (mean+/-S.E.M.: 17.5+/-1.7) and corpora lutea from 0 to 50 (mean+/-S.E.M.: 17.0+/-1.6). The BFV increased from 28.4 to 45.0 ml/min between Days 10 and 13 and reached a maximum of 108.5 ml/min on Day 7(p.i.) The PI decreased from 6.25 on Day 10 to 4.70 on Day 13 and to 2.10 on Day 7(p.i.) The BFV and PI on Day 13 did not correlate with the number of follicles (P>0.05). However, on Day 7(p.i.) the number of corpora lutea correlated positively with the BFV (r=0.64; P<0.0001), and an inverse relationship was found for the PI (r=-0.51; P=0.0005). There were no correlations (P>0.05) between the BFV and PI on Day 10 and the number of follicles on Day 13 or the number of corpora lutea on Day 7(p.i.) Results of the present study show that in cows, a hormonal treatment to induce a superovulatory response yielded a marked increase in BFV and a marked decrease in PI in the ovarian artery. However, there was no correlation between BFV and PI in the ovarian arteries before hormonal stimulation and the number of follicles and corpora lutea that developed after stimulation. Thus BFV and PI measured in the ovarian arteries have limited diagnostic value to predict the outcome of a gonadotropin treatment.

Gonadotropin preparations: past, present, and future perspectives.

This Educational Bulletin offers past, present and future perspectives on gonadotropin preparations.

Efecto de la sincronización del estro con prostaglandina-f2a vs CIDR + 500 UI de eCG en ovejas bergamacia durante el inicio de la fase luteal / Effect of estrus synchronization with prostaglandins-F2a vs CIRD + 500 IU of eCG in bergamacia ewes during early luteal phase

Con el objeto de evaluar los efectos de la sincronización del estro con PGF2a vs CIDR + 500 UI de eCG, sobre el tiempo de presentación de estro, ovulación y las concentraciones plasmáticas de hormonas esteroidales durante el inicio de la fase luteal en ovejas, se seleccionaron 14 hembras Bergamacia distribuidas en dos grupos: el Grupo uno (Control), sometido a dos aplicaciones de prostaglandina-F2a (PG), con un intervalo de nueve días, y el Grupo dos, tratado con el dispositivo intravaginal impregnado con progesterona (CIDR) durante 12 días y 500 UI de eCG. La presentación del estro fue de 100%. Entretanto, el intervalo estro-ovulación fue de 36,0 ± 0,72 horas en el grupo dos. El grupo control tratado con PG presentó un intervalo estro-ovulación de 53,42 ± 3,0 horas (P<0,001). Hubo diferencia significativa (P<0,01) en las concentraciones plasmáticas de P4 entre los tratamientos. Los animales del Grupo dos presentaron aumentos significativos (P < 0,01) en las concentraciones plasmáticas de P4, desde el sexto hasta el décimo día después de la ovulación, comparados con las concentraciones de los animales control. Del mismo modo, también se constató una diferencia significativa en la interacción tratamiento y día (P< 0,05). Las concentraciones de E2 en el plasma sanguíneo fueron estadísticamente diferentes (P< 0,001) entre el grupo control y el grupo sincronizado con el CIDR + eCG. Fueron observadas diferencias significativas (P< 0,001) en las concentraciones plasmáticas de E2 entre los tratamientos después del día ovulatorio (día cero), siendo además constatada diferencia significativa entre los días (P< 0,001) y en la interacción tratamiento y día (P< 0,05). Se puede concluir que, la sincronización del estro en hembras Bergamacia, utilizando el CIDR + eCG disminuyó el intervalo estro-ovulación y provocó aumento de las hormonas esteroidales en plasma.

An experiment was conducted to investigate the effects of estrous synchronization with PGF2a vs cidr + 500 IU of eCG on interval to estrus, ovulation and steroidal hormones plasma concentrations during early luteal phase in sheep. Fourteen ewes were treated, distributed in two groups: Group 1 (Control), synchronized with two injections of prostaglandin-F2a (PG), given 9 days apart, and Group 2, was treated with CIDR for 12 days and 500 IU of eCG. Estrous presentation was 100%. The interval estrus-ovulation was 36.0 ± 0.72 h in Group two. The control group presented an interval estrus-ovulation of 53.42 ± 3.0 hours (P<0.001).There were significant difference (P < 0.01) in P4 plasma concentrations among treatments. In Group 2, the animals showed significatives increases (P < 0.01) in P4 plasma concentrations during day 6 until day 10 when compared with control animals. It was observed significative difference at interaction treatment by day (P < 0.05). E2 plasma concentrations were statistically differents (P < 0.001) among control group and synchronized group with CIDR + eCG. There were significant difference (P < 0.001) in E2 plasma concentrations among treatments after ovulation day (Day 0) with significative difference among days (P < 0.001) and interaction treatment x day (P < 0.05). These results indicated that estrous synchronization in Bergamacia females, using CIDR + eCG diminished interval estrus-ovulation and elicit higher levels of steroidal hormones in plasma.

eFSH in clinical equine practice.

Equine follicle stimulating hormone (eFSH) has been used to induce follicular development in transitional mares and problem acyclic mares, as well as superovulate cycling mares. The most efficacious protocol is to administer 12.5 mg eFSH, intramuscularly, twice daily beginning 5 to 7 days after ovulation when the diameter of the largest follicle is 20 to 25 mm. Prostaglandins are to be administered on the second day of eFSH therapy. Treatment with eFSH is continued for 3 to 5 days until follicle(s) are >or=35 mm in diameter. The mare is subsequently allowed to 'coast' for 36 h, after which human chorionic gonadotropin is administered to induce ovulation.

Improvement of follicular development rather than gonadotrophin secretion by thyroxine treatment in infertile immature hypothyroid rdw rats.

Despite extensive study of reproductive abnormalities in female hypothyroid animals, little is known of folliculogenesis and gonadotrophin secretion in spontaneously hypothyroid animals, especially in response to exogenous hormone treatment. In this study, follicular development and plasma hormone concentrations in the presence or absence of thyroxine and eCG treatment were investigated in infertile immature spontaneously hypothyroid rdw rats. Administration of thyroxine once a day from day 21 to day 29 after birth resulted in increases in body weight (P < 0.001) and ovary mass on day 30 (P < 0.01). Similar populations of both healthy and atretic antral follicles ranging from 101 to 400 micrometer in diameter were observed in control rdw and normal rats. In rdw rats, thyroxine treatment markedly increased the number of healthy antral uniovular follicles 101-400 or > 550 micrometer in diameter in the absence or presence of eCG, respectively. Combined treatment of thyroxine and eCG in rdw rats also markedly increased the number of healthy antral biovular follicles. Thyroxine treatment did not affect the population of atretic antral follicles, but resulted in decrease in the number of atretic large antral follicles (> 400 microm) in the presence of eCG. Plasma oestradiol concentrations in rdw rats given both thyroxine and eCG were significantly higher than they were in rdw rats given eCG alone (P < 0.001). There were no significant differences in plasma FSH concentrations on day 28 between rdw (10.7 +/- 1.6 ng ml(-1)) and normal rats (12.0 +/- 1.4 ng ml(-1); P > 0. 05). Although there were no significant differences in plasma LH concentrations between control rdw (1.9 +/- 0.1 ng ml(-1)) and normal rats on day 30 (1.8 +/- 0.1 ng ml(-1); P > 0.05), eCG treatment increased plasma LH to a peak concentration 52 h after injection in normal (24.9 +/- 2.4 ng ml(-1)) but not in rdw rats treated with thyroxine (4.8 +/- 0.3 ng ml(-1); P < 0.05). In conclusion, the results of the present study indicate that thyroxine treatment improves follicular development but does not rescue the defect of the preovulatory surge of LH in eCG-primed rdw rats.

Changes in plasma testosterone and testicular transferrin concentration, testicular histology and semen quality after treatment of testosterone-depot plus PMSG to 3 dogs with asthenozoospermia.

Three dogs diagnosed as having asthenozoospermia were given three intramuscular injections of 50 mg testosterone(T)-depot plus 250 IU pregnant mare serum gonadotropin (PMSG) at 2-week intervals, and their plasma T and testicular transferrin (Tf) concentrations, testicular histology, and semen quality were examined during the period of hormone therapy. Plasma T concentrations temporarily increased, and there was a slight improvement in spermatogenesis. Increased Tf concentrations suggested that Sertoli cell function in all three dogs was promoted by hormone treatment. The results showed that semen quality, especially the percentages of motile sperm and abnormal sperm, were improved between 1 and 5 weeks after the start of T-depot plus PMSG treatment.

Birth of Siberian tiger (Panthera tigris altaica) cubs after transvaginal artificial insemination.

A captive 9-yr-old female Siberian tiger (Panthera tigris altaica) at the Lisbon Zoo was treated with equine chorionic gonadotropin followed 80 hr later by human chorionic gonadotropin to stimulate follicular development and ovulation, respectively. Forty-one hours after the second hormone administration, the tiger was subjected to transvaginal artificial insemination with diluted fresh semen containing 500 x 10(6) motile spermatozoa obtained from an 8-yr-old male Siberian tiger via electroejaculation. After anesthesia, the female tiger was placed in an inclined position with the hind limbs elevated during and after the insemination and was maintained in this position for 15 min to minimize semen reflux. An anesthetic reversal agent was then administered. After a 103-day gestation, the female gave birth to three apparently healthy cubs that survived 24-48 hr. These results demonstrate that transvaginal artificial insemination can be successfully performed in the Siberian tiger to produce full-term offspring.

Early development and location of embryos in the reproductive tract of Nili Ravi buffalo (Bubalus bubalis): a retrospective analysis.

One year data on embryo recovery were analyzed to study the development and descent of preimplantation embryos in Nili Ravi water buffalo. Forty-five superovulatory attempts were performed on 23 buffalo. A total of 45 embryos were recovered either nonsurgically or after slaughtering the animals at various time intervals (85 to 176 h) post estrus. Embryos were located in the oviducts at 85 h after estrus. At 108 h post estrus, most of them (78%) were recovered from the uteri. The embryos had 8 to 16 cells at 85 h post estrus, grew to morulae at 108 h and to compact morulae at 125 h post estrus. Early blastocysts were observed at 141 h post estrus. Blastocysts were predominant (69%) at 156 to 176 h after estrus; no hatched blastocysts were recovered during this time interval. Based on our findings, embryo recovery at around 150 h post estrus (i.e., Day 6 of the cycle) is recommended for compact morulae or blastocysts in the water buffalo.

Influence of flushing on LH secretion, follicular growth and the response to estrus synchronization treatment in suckled beef cows.

The effects of energy supplementation (flushing) on LH and estradiol secretion, follicular growth and the response to estrus synchronization treatment (Norgestomet + PMSG initiated 41.9 +/- 3.4 d after calving) were investigated in 16 suckled beef cows fed either 70% (Group C, n = 8) of energy requirements from calving to 3 wk after AI or fed the same restricted diet until 11 d before synchronization and then were supplemented with 2 kg concentrate until 3 wk after AI (Group S, n = 8). Concentrations of LH and estradiol 17 beta were measured from 3 sampling periods: 25 and 39 d after calving and between 29 and 49 h after implant removal. Ovaries were examined by ultrasonography 11 d before treatment to implant withdrawal (IR). The effects of energy level, day (or hour) of observation and corresponding interactions were tested on repeated measurements by split-plot ANOVA. No positive effect of flushing was observed on characteristics of LH secretion on Day 39. However, the size of the largest follicle and the number of large follicles were higher in Group S than in Group C cows, respectively, 7 and 9 d after the beginning of flushing to 2 d after the start of treatment. After IR, the estradiol secretion tended to be higher in Group S than in Group C cows (9.8 +/- 0.4 pg/mL vs 7.2 +/- 0.2 pg/mL; P = 0.06), but no effect on LH secretion was observed. After implant removal 12 cows ovulated (Group S: 7/8 vs Group C: 5/8; P > 0.05), 7 were pregnant at 21 d after AI (Group S: 6/8 vs Group C: 1/8; P < 0.05) and 4 at 45 d after AI (Group S: 4/8 vs Group C 0/8; P > 0.05). To conclude, flushing had a positive effect on follicular growth, which does not seem to be mediated by LH. In cows fed a restricted diet, flushing enhanced follicular growth, increased the fertilization rate and/or reduced early embryonic death.

Induçäo de ovulaçäo em fêmeas de camundongos albinas CF1 imaturas e adultas com gonadotrofina sérica de éguas grávidas e gonadotrofina coriônica humana: avaliaçäo da taxa de ovulaçäo e fertilizaçäo e do número de oócitos e embriöes recuperados / Ovulation induction in immature and adults swiss CF1 female mice with pregnant mare serum gonadotrophin and human chorionic gonadotrophin: evaluation of ovulation and fertilization rates and the number of the oocytes and embryos recovered

A superovulaçäo de fêmeas de camundongos com gonadotrofinas é um procedimento utilizado desde o início do século, visando a maior produçäo de oócitos e embriöes para serem utilizados como controle de qualidade em reproduçäo assistida animal e humana. Objetivamos, com as doses de gonadotrofinas utilizadas, avaliar qual grupo de fêmeas de camundongos imaturas e adultas apresentava melhores resultados em relaçäo à taxa de ovulaçäo e de fertilizaçäo, além do número de oócitos e embriöes recuperados. Resultados significativamente melhores em todos os parâmetros avaliados foram obtidos nos animais imaturos e adultos induzidos a superovular em relaçäo aos grupos-controles, com exceçäo da taxa de fertilizaçäo, na qual näo houve diferenças significativas entre os animais adultos com ciclo estral natural e os induzidos a superovular. Os animais imaturos e adultos que receberam gonadotrofinas tiveram comportamento similar no que diz respeito à taxa de ovulaçäo e ao número de oócitos e embriöes recuperados. No entanto, a taxa de fertilizaçäo no grupo de fêmeas imaturas foi significativamente superior àquela exibida pelos animais adultos. O trabalho sugere o grupo de fêmeas de camundongos imaturas, quando se objetiva a recuperaçäo de embriöes devido à maior taxa de fertilizaçäo mostrada neste grupo.