Influence of norgestomet in combination with gonadotropins on induction of estrus and ovulation in prepubertal gilts.
(25/1572)
Our objective was to determine whether priming with the progestogen norgestomet for 9 d would enhance estrual and ovulatory responses of prepubertal gilts to PG600 (400 IU eCG + 200 IU hCG). Gilts (140 to 190 d old) were assigned by litter, age, and weight to one of three treatments: 1) 9 d of norgestomet implant with an injection of PG600 after implant removal on d 9 (N+PG; n = 43); 2) no implant and an injection of PG600 on d 9 (PG; n = 36); or 3) neither implant nor PG600 (control; n = 29). Beginning on d 0, gilts were exposed once daily to a boar and checked until estrus was observed or until d 45 after the start of the experiment. Ovaries were examined for number of corpora lutea (CL) after estrus or at 45 d. Greater proportions of N+PG (63%, P < .05) and PG (69%, P < .01) gilts expressed estrus than did controls (34%), but proportions did not differ between N+PG and PG (P > .10). Among gilts in estrus following treatment with N+PG or PG, 100% showed estrus within 6 d after PG600 injection. For gilts that expressed estrus within 45 d, the average age at estrus was reduced (P < .05) by PG to 172 +/- 2 d compared with 182 +/- 4 d for controls. Average age at estrus did not differ (P > . 10) between PG and N+PG (177 +/- 2 d). Greater proportions of N+PG (82%; P < .001) and PG (65%; P < .001) gilts ovulated than controls (13%), but proportions did not differ between N+PG and PG (P > .10). The number of CL (20 +/- 2) was not affected by treatment and ranged from 2 to 71. There was no increase in ovarian cysts in response to treatment. Results indicated that norgestomet before PG600 did not enhance estrus expression or ovulation compared with PG600 alone, but use of PG600 increased the proportions of gilts that expressed estrus and ovulated compared with controls. (+info)
Hormonal regulation of natriuretic peptide system during induced ovarian follicular development in the rat.
(26/1572)
All components of the natriuretic peptide (NP) system have been found in the ovary. The purpose of this study was to determine the hormonal regulation of the NP system during follicular growth and ovulation induced by gonadotropins eCG and hCG. Ovarian membrane binding, before and after treatment, revealed the presence of guanylyl cyclase-type receptors exclusively. Equine CG treatment increased Bmax from 225 +/- 50 fmol/mg protein in control animals to 354 +/- 51 fmol/mg protein, and additional hCG treatment increased it further to 492 +/- 130 fmol/mg protein (p < 0.05), without changing receptor affinity. The increased binding was consistent with increased ability of atrial natriuretic peptide (ANP) to activate guanylyl cyclase in the ovarian cells obtained from hormone-treated animals. In confirmation, autoradiography of 125I-tyroCNP and 125I-ANP binding to the rat ovary showed that both guanylyl cyclase GC-A and GC-B receptor subtypes are localized to the granulosa cells of antral follicles. Quantitative analysis of GC-A and GC-B receptors by reverse transcription-polymerase chain reaction showed that the expression level of both receptors started to increase at 2 h and reached maximal levels at 6 h following eCG treatment. Increased levels of GC-B mRNA were also observed 12 h after eCG injection. At 24 and 48 h the receptor levels were below basal. Stimulation of NP receptors by eCG was paralleled by activation of both ovarian ANP and C-type natriuretic peptide (CNP) gene expression. ANP mRNA increased as early as 1 h after eCG injection and remained elevated up to 6 h. CNP mRNA increased at 2 h after eCG injection, peaked (5-fold) at 6 h, and remained elevated 48 h later, a stage at which follicular maturation continues. Incubation of ovaries with ANP significantly decreased eCG-induced estradiol level, indicating the functionality of the ovarian NP system. These results implicate the NP system in the induction and maintenance of fluid balance in the rapidly developing ovarian follicle. (+info)
Humoral immune response to equine chorionic gonadotropin in ewes: association with major histocompatibility complex and interference with subsequent fertility.
(27/1572)
In dairy ewes, the use of eCG as a convenient hormone for the induction of ovulation is necessary for out-of-season breeding and artificial insemination (AI). In this report we show the presence of anti-eCG antibodies in plasma of treated ewes. The major histocompatibility complex (MHC) was involved in the individual variability of the humoral immune responses to eCG. We found significant associations between the anti-eCG response phenotype and some MHC class II alleles. The low immune response phenotype was associated with one MHC class II allele only in Lacaune ewes, and the high immune response phenotype was associated with one MHC class II allele both in Manech and in Lacaune ewes. In herds, the impact of residual anti-eCG antibodies on subsequent fertility after AI seems minimal because of an indirect elimination of high-responder ewes from AI breeding. Therefore, the true magnitude of the association between residual anti-eCG antibody concentration and fertility has been underestimated. An additional experiment without any high-responder female elimination showed a significant correlation between high residual antibody concentrations and lower lambing rate after AI at a fixed time, possibly because of a delayed preovulatory LH surge. The results suggest that anti-eCG antibody concentration is one risk factor for infertility after AI. (+info)
Adjuvant L-arginine treatment for in-vitro fertilization in poor responder patients.
(28/1572)
The objective of the present study was prospectively and randomly to evaluate the role of L-arginine in improving uterine and follicular Doppler flow and in improving ovarian response to gonadotrophin in poor responder women. A total of 34 patients undergoing assisted reproduction was divided in two groups according to different ovarian stimulation protocols: (i) flare-up gonadotrophin-releasing hormone analogue (GnRHa) plus elevated pure follicle stimulating hormone (pFSH) (n = 17); and (ii) flare-up GnRHa plus elevated pFSH plus oral L-arginine (n = 17). During the ovarian stimulation regimen, the patients were submitted to hormonal (oestradiol and growth hormone), ultrasonographic (follicular number and diameter, endometrial thickness) and Doppler (uterine and perifollicular arteries) evaluations. Furthermore, the plasma and follicular fluid concentrations of arginine, citrulline, nitrite/nitrate (NO2-/NO3-), and insulin-like growth factor-1 (IGF-1) were assayed. All 34 patients completed the study. In the L-arginine treated group a lower cancellation rate, an increased number of oocytes collected, and embryos transferred were observed. In the same group, increased plasma and follicular fluid concentrations of arginine, citrulline, NO2-/NO3-, and IGF-1 was observed. Significant Doppler flow improvement was obtained in the L-arginine supplemented group. Three pregnancies were registered in these patients. No pregnancies were observed in the other group. It was concluded that oral L-arginine supplementation in poor responder patients may improve ovarian response, endometrial receptivity and pregnancy rate. (+info)
Bioequivalence of subcutaneous injections of recombinant human follicle stimulating hormone (Puregon(R)) by Pen-injector and syringe.
(29/1572)
A randomized, single-centre, cross-over study was designed to compare the bioavailability of two pharmaceutical formulations of recombinant human follicle stimulating hormone (recFSH; Puregon(R)): (i) a dissolved cake injected by a normal syringe; and (ii) a ready-for-use solution injected using a device referred to as Puregon(R)Pen. Twenty-two healthy female volunteers underwent one of two administration sequences: Puregon(R)Pen/syringe or syringe/Puregon(R)Pen, by which they received a single subcutaneous dose of recFSH (150 IU). Endogenous gonadotrophin production had been previously suppressed using an oral contraceptive (Lyndiol(R)). Pharmacokinetic parameters characterizing rate [peak concentration (Cmax) and time of peak concentration (tmax)] and extent [area under the curve (AUC) and clearance (CL)] of absorption were obtained from 20 subjects. After injection with both formulations, serum FSH concentrations reached a peak of 3.4 IU/l at 13 h after injection. The elimination half-life was approximately 34 h, irrespective of formulation. A difference of approximately 18% was found between serum FSH concentrations obtained using the two formulations, which was caused by differences between the anticipated and the actual volume injected with the normal syringe. After correction for injection losses by weighing the amount injected with a normal syringe, the two formulations were found to be bioequivalent with respect to Cmax, AUC and CL. For tmax, bioequivalence could not be proven due to high intra-subject variability and broad absorption peaks of FSH. Both methods were well tolerated, local reactions being generally mild and short-lived. (+info)
Recurrent empty follicle syndrome successfully treated with recombinant human chorionic gonadotrophin.
(30/1572)
We report a case of a patient with polycystic ovary syndrome and primary infertility who was admitted to our in-vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) programme because of her partner's severe oligozoospermia and asthenozoospermia. Ovarian stimulation was accomplished in the three treatment cycles using gonadotrophin therapy after a dual approach with ovarian suppression using oral contraceptive pills followed by gonadotrophin-releasing hormone agonist therapy. Oocyte retrieval was unsuccessful in the first two treated cycles despite the fact that human chorionic gonadotrophin (HCG) from three different batches was used. In the third treatment cycle, recombinant HCG was used and five oocytes were retrieved. This is the first report of recurrent empty follicle syndrome despite the use of different batches of commercially available urinary HCG, and of its successful treatment using recombinant HCG. (+info)
Severe ovarian hyperstimulation syndrome following salvage of empty follicle syndrome.
(31/1572)
We report a case of severe ovarian hyperstimulation syndrome (OHSS) following a rescue of empty follicle syndrome (EFS). This suggests that the risk of developing OHSS remains unaltered even in the presence of EFS. The case supports the possibility of obtaining oocytes that fertilize and cleave normally after a second dose of human chorionic gonadotrophin (HCG) and a repeat oocyte retrieval. It supports the suggestion that the follicles are not necessarily empty in EFS. It demonstrates further that OHSS cannot be prevented by aspiration of follicular fluid and patients with large numbers of follicles and EFS must be warned of this potential complication. (+info)
Embryo development and pregnancies from in-vitro matured and fertilized human oocytes.
(32/1572)
There is an increasing interest in retrieving immature oocytes in the absence of or with limited gonadotrophin exposure, with the aim of maturing them in vitro for embryo transfer purposes. The aim of this report is to present our experience of fertilization, embryonic development and pregnancies from in-vitro maturation cycles. A total of 18 patients underwent 21 cycles in which an average of 8.1 immature oocytes was retrieved after limited exposure to human menopausal gonadotrophin (HMG) and no exposure to human chorionic gonadotrophin (HCG). In one cycle, no oocytes were recovered. The oocytes were cultured for 44 h and 121 oocytes which reached MII were injected with a single spermatozoon. A total of 71 oocytes showed two pronuclei and 53 zygotes cleaved. Forty-four embryos were transferred in 17 cycles. Five weeks after embryo transfer, ultrasound examination indicated the presence of one gestational sac and one fetal heart beat in two patients. The results suggest that in-vitro matured oocytes can undergo fertilization and the resulting embryos may result in pregnancies. However, the success rate was not sufficient to recommend widespread use of the technique without further research. (+info)