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1.
Theriogenology ; 172: 8-19, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34082223

RESUMO

Equine chorionic gonadotropin (eCG) is a heterodimeric glycoprotein hormone produced by pregnant mares that has been used to improve reproductive performance in different domestic species. Several strategies to produce the hormone in a recombinant way have been reported; nevertheless, no approach has been able to produce a recombinant eCG (reCG) with significant in vivo bioactivity or in sufficient quantities for commercial purposes. For this reason, the only current product available on the market consists of partially purified preparations from serum of pregnant mares (PMSG). Herein, we describe a highly efficient process based on third-generation lentiviral vectors as delivery method for the production of reCG in suspension CHO-K1 cells, with productivities above 20 IU 106 cell-1.d-1 and 70% purification yields after one purification step. Importantly, reCG demonstrated biological activity in cattle, since around 30 µg of reCG were needed to exert the same biologic effect of 400 IU of PMSG in an ovulation synchronization protocol. The results obtained demonstrate that the developed strategy represents an attractive option for the production of reCG and constitutes an auspicious alternative for the replacement of animals as a source of PMSG.


Assuntos
Gonadotropina Coriônica , Gonadotropinas Equinas , Animais , Células CHO , Bovinos , Gonadotropina Coriônica/farmacologia , Cricetinae , Cricetulus , Feminino , Gonadotropinas Equinas/farmacologia , Cavalos , Ovulação , Gravidez
2.
Theriogenology ; 77(8): 1679-85, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22401834

RESUMO

Three experiments were designed to evaluate the superovulatory response of beef cows following two intramuscular (IM) administrations 48 h apart of Folltropin-V diluted in reduced concentrations of hyaluronan (Split-single IM administrations; Experiment 1-300 mg Folltropin-V on the first day and 100 mg 48 h later; Experiment 2-200 mg Folltropin-V on the first day and 100 mg 48 h later). In Experiments 1 and 2, superovulatory response and ova embryo/embryo production did not differ between donors receiving twice daily IM of Folltropin-V over 4 days and those given a Split-single IM administration of Folltropin-V diluted in 10 mg/mL hyaluronan solution. Experiment 3 compared Split-single IM administration of Folltropin-V diluted in two hyaluronan concentrations (5 or 10 mg/mL) with Folltropin-V diluted in saline and administered twice-daily over 4 days. Beef cows (17 Angus and 12 Simmental) were randomly assigned to one of three treatment groups to be superstimulated three times in a cross-over design, so that all cows received all treatments. A total dose of 300 mg Folltropin-V was divided into twice-daily IM over 4 days, or in two IM treatment 48 h apart (200 mg on first day and 100 mg 48 h later) in the hyaluronan groups. Mean (± SEM) numbers of transferable embryos did not differ among treatment groups (Control: 4.0 ± 0.8; 10 mg/mL hylauronan: 5.0 ± 0.9; 5 mg/mL hyaluronan: 6.1 ± 1.3). We concluded that the Split-single IM administration of Folltropin-V diluted in either concentration of hyaluronan resulted in a comparable superovulatory response to the traditional twice-daily protocol.


Assuntos
Hormônio Foliculoestimulante/farmacologia , Indução da Ovulação/veterinária , Ovulação/efeitos dos fármacos , Superovulação/efeitos dos fármacos , Animais , Bovinos , Feminino , Hormônio Foliculoestimulante/administração & dosagem , Injeções Intramusculares/veterinária , Folículo Ovariano/diagnóstico por imagem , Folículo Ovariano/efeitos dos fármacos , Indução da Ovulação/métodos , Ultrassonografia
3.
Anim Reprod Sci ; 129(1-2): 7-13, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22115521

RESUMO

The need to inject FSH twice daily for superstimulation of ovarian follicular development in cattle necessitates frequent attention by farm-personnel and increases the possibility of failures due to mishandling and errors in administration of treatments. A series of three experiments were designed to evaluate the feasibility of superstimulation in beef cattle with a single intramuscular (IM) injection of Folltropin-V diluted in a hyaluronan-based slow-release formulation (SRF). In Experiment 1, cows were assigned to one of three treatment groups to compare two methods of injection as compared to the twice daily IM injection protocol. Superovulatory response of cows (n=6) treated with twice daily IM injections over 4 days (Control) was greater than of cows treated with a single subcutaneous (SC) injection in SRF (n=6), while superovulatory response of cows treated with a single IM injection in SRF (n=6) was intermediate. Experiment 2 was designed to compare two concentrations of SRF (20mg/mL hyaluronan, 100% compared to 10mg/mL hyaluronan, 50%) in a single IM injection protocol. The mean number of corpora lutea (CL) were not significantly different (P≥0.05), but the numbers of total ova/embryos (P<0.05), fertilized ova (P<0.01) and transferable embryos (P<0.001) were greater in cows treated with FSH in 100% SRF (n=20) than cows treated with FSH in 50% SRF (n=20). Experiment 3 was designed to compare superovulatory response in Red Angus donor cows treated with a single IM injection of Folltropin-V diluted in 100% solution of SRF with those treated with the traditional twice-daily IM injection protocol over 4 days. Mean (±SEM) numbers of CL (13.7±1.2 compared to 13.8±1.2), total ova/embryos (12.3±1.5 compared to 13.7±2.1), fertilized ova (7.2±1.1 compared to 8.4±1.4) and transferable embryos (4.9±0.8 compared to 6.4±1.3) were not significantly different between Control (n=29) and Single injection (n=29) groups, respectively. In summary, superstimulation of beef donor cows with a single IM injection of Folltropin-V diluted in 100% solution of SRF resulted in a comparable superovulatory response to the traditional twice-daily IM administration of Folltropin-V diluted in saline over 4 days.


Assuntos
Bovinos/fisiologia , Hormônio Foliculoestimulante/administração & dosagem , Folículo Ovariano/fisiologia , Superovulação/fisiologia , Animais , Corpo Lúteo/diagnóstico por imagem , Corpo Lúteo/fisiologia , Feminino , Fertilização in vitro/veterinária , Injeções Intramusculares/veterinária , Distribuição Aleatória , Ultrassonografia
4.
Reprod Fertil Dev ; 22(1): 106-12, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20003851

RESUMO

There is continuing need to simplify bovine superovulation protocols without compromising embryo production. The control of follicular wave emergence and ovulation has facilitated donor management, but the most commonly used treatment, oestradiol, cannot be used in many parts of the world and mechanical removal of the dominant follicle is difficult to apply in the field. Other alternatives include gonadotrophin-releasing hormone (GnRH) or LH, but efficacy in groups of randomly cycling animals is variable. Another alternative is to increase the response to GnRH by inducing a persistent follicle and initiating FSH treatments following GnRH-induced ovulation. The number of transferable embryos following superovulation during the first follicular wave did not differ from that achieved 4 days after oestradiol benzoate and progesterone. To further simplify superovulation, FSH has been administered as a single intramuscular injection. Superovulation of beef donors with a single intramuscular injection of Folltropin-V (Bioniche Animal Health, Belleville, ON, Canada) diluted in a slow-release formulation resulted in embryo production comparable to that obtained using the traditional twice-daily protocol. The single intramuscular injection has the potential to reduce labour and handling and may be useful when handling stress is an impediment to success. These alternatives provide ways of facilitating widespread application of embryo transfer technologies.


Assuntos
Cruzamento/métodos , Bovinos/fisiologia , Sincronização do Estro/métodos , Superovulação/fisiologia , Animais , Transferência Embrionária/métodos , Transferência Embrionária/veterinária , Estradiol/farmacologia , Feminino , Hormônio Foliculoestimulante/farmacologia , Hormônio Liberador de Gonadotropina/farmacologia
5.
Acta sci. vet. (Impr.) ; 38(supl.2): s278-s286, 2010. ilus
Artigo em Inglês | VETINDEX | ID: biblio-1411385

RESUMO

Background: Successful bovine embryo transfer programs require the use of simple superovulation protocols and high numbers of transferable embryos. The control of follicular wave emergence and ovulation have facilitated donor management, but the most commonly used treatment, estradiol, cannot be used in many parts of the world, and mechanical removal of the dominant follicle is difficult to apply in the field. Other alternatives include GnRH or LH, but efficacy in groups of randomly cycling animals is variable. Review: An alternative treatment to control follicular wave emergence is to increase the response to GnRH by inducing a persistent follicle and initiating FSH treatments following GnRH-induced ovulation. The number of transferable embryos following superovulation during the first follicular wave arising at the time of the GnRH-induced ovulation did not differ from that achieved 4 days after treatment with estradiol benzoate and progesterone. To further simplify superovulation, FSH has been diluted in a slow-release formulation (SRF) and administered as a single or a split intramuscular injection. Although, a single intramuscular injection of Folltropin-V in SRF was highly efficacious in the induction of superovulation in a variety of breeds of beef cattle, it was difficult to mix with Folltropin-V. However, in a subsequent series of experiments it was shown that reducing the initial concentration of SRF to 25% and administering the Folltropin-V as two intramuscular injections 48 hours apart (called split-single administration) facilitated the dilution of Folltropin-V with the SRF and resulted in a superovulatory response that did not differ from controls. Conclusion: The incorporation of GnRH-based protocol to control follicular dynamics and ovulation have the advantage of being able to schedule the treatments quickly and without the need for detecting estrus in donor cows. The single split intramuscular injection of Folltropin-V in 25% SRF has the potential to reduce labor and handling and may be useful when handling stress is an impediment to success. These treatments are practical and easy to perform by the farm staff, facilitating the widespread application of embryo transfer technologies.


Assuntos
Animais , Bovinos , Superovulação , Hormônio Liberador de Gonadotropina/administração & dosagem , Estradiol/administração & dosagem , Hormônio Foliculoestimulante , Transferência Embrionária/veterinária
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