The objective was to determine the effects of immunocastration (Improvest) on reproductive characteristics in boars. Seventy-two boars were used in a randomized design with three treatments: single injection (SI) or double injection (DI) of Improvest, and intact controls (no Improvest; CNT) (n = 24/group). At wk 10, 15, 20, 25, and 40, blood was collected and serum harvested to evaluate testosterone concentrations via RIA. At wk 25, 18 pigs (n = 6/ group) were sacrificed and testes were removed, weighed, and measured. Libido was assessed at 32, 36, 47, 60, and 63+ wk of age (1 to 5; 1 = no libido; 5 = high libido) and semen collected beyond 60 wk of age. Testosterone concentrations were less for DI boars compared to CNT boars and SI boars at 20 and 25 wk of age (P < 0.001), but not different at 40 wk of age. All testicular measurements and weight were less for DI boars compared to SI and CNT boars (P < 0.001). There was no treatment effect on libido between 32 to 63+ wk of age. Semen volume, gel weight and total number of sperm cells were not different among treatments. Sperm concentration was greater for DI than SI (P = 0.011), and tended to be greater for DI compared to CNT (P = 0.102). Sperm motility tended to be greater for DI boars compared to CNT boars (P = 0.066). The results show that there are no permanent effects of immunocastration on reproductive characteristics in boars. / Master of Science

Submitted by Maria Beatriz Vieira (mbeatriz.vieira@gmail.com) on 2017-10-18T12:27:24Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) dissertacao_livia_budziarek_eslabao.pdf: 1788001 bytes, checksum: c14f927ac7e6babdc2bd66cf80275556 (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2017-10-23T11:12:08Z (GMT) No. of bitstreams: 2 dissertacao_livia_budziarek_eslabao.pdf: 1788001 bytes, checksum: c14f927ac7e6babdc2bd66cf80275556 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2017-10-23T11:12:21Z (GMT) No. of bitstreams: 2 dissertacao_livia_budziarek_eslabao.pdf: 1788001 bytes, checksum: c14f927ac7e6babdc2bd66cf80275556 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-10-23T11:12:30Z (GMT). No. of bitstreams: 2 dissertacao_livia_budziarek_eslabao.pdf: 1788001 bytes, checksum: c14f927ac7e6babdc2bd66cf80275556 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-03-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / A imunocontracepção é reconhecida como um dos principais novos métodos contraceptivos para o controle e o manejo da fertilidade em diferentes espécies animais. Dentre os potenciais alvos utilizados em vacinas contraceptivas, o hormônio liberador de gonadotrofinas (GnRH) é considerado um dos mais atrativos. O GnRH é um decapeptídeo hipotalâmico que apresenta um papel central na reprodução de mamíferos. Entretanto, devido à sua baixa imunogenicidade, é necessário associar o GnRH com uma molécula carreadora capaz de estimular o sistema imune como, por exemplo, a subunidade B da enterotoxina termolábil de Escherichia coli (LTB). O presente estudo visou avaliar o potencial imunocontraceptivo de duas quimeras LTB/GnRH em camundongos machos da linhagem BALB/c. Os camundongos foram divididos aleatoriamente em oito grupos experimentais. O grupo LTB/GnRH-P recebeu a quimera expressa em P. pastoris. O grupo LTB/GnRH-P/A recebeu a quimera expressa em P. pastoris adsorvida em adjuvante oleoso. O grupo LTB/GnRH-E recebeu a quimera expressa em E. coli. O grupo LTB/GnRH-E/A recebeu a quimera expressa em E. coli adsorvida em adjuvante oleoso. O grupo LTB recebeu a proteína LTB expressa em E. coli. Os grupos Controle e Controle/A não receberam nenhum antígeno vacinal. O grupo Vacina comercial recebeu vacina comercial anti-GnRH utilizada em bovinos. A resposta imune humoral foi avaliada pela técnica de ELISA indireto e o potencial imunocontraceptivo foi avaliado por meio da quantificação de testosterona sérica e das análises histológicas das gônadas dos animais. Os grupos que receberam os antígenos LTB/GnRH (25 μg por vacina) apresentaram níveis de IgG total significativamente superiores quando comparados aos grupos controle, mostrando que ambos os antígenos são imunogênicos. Os grupos LTB/GnRH-P e LTB/GnRH-P/A apresentaram as maiores absorbâncias nos dias 28 (1,11 ± 0,09) e 42 (1,44 ± 0,04), respectivamente. Além disso, o grupo LTB/GnRH-P/A apresentou níveis de testosterona significativamente menores ao controle a partir do dia 28 (192 ng/dl ± 254,55). Os grupos LTB/GnRH-E e LTB/GnRH-E/A também obtiveram os maiores níveis de anticorpos nos dias 28 (0,33 ± 0,005) e 42 (1,44 ± 0,08), respectivamente. O grupo LTB/GnRH-E/A apresentou níveis de testosterona significativamente menores ao controle a partir do dia 28 (<12 ng/dl ± 0). Os resultados da histologia mostraram que ambos os antígenos causam alterações na espermatogênese, sendo que o antígeno expresso em E. coli foi relacionado com as maiores alterações nas gônadas. O presente estudo mostrou quimeras produzidas através da fusão da LTB com uma única molécula de GnRH é capaz de induzir a geração de resposta imune humoral, bloqueio das funções endócrinas relacionadas com a reprodução e alterações teciduais nas gônadas de camundongos machos. / Immunocontraception is recognized as one of the major new contraceptive methods for the control and management of fertility in different animal species. Among the potential targets used in contraceptive vaccines, gonadotropin-releasing hormone (GnRH) is considered one of the most attractive. GnRH is a hypothalamic decapeptide that presents a central role in mammalian reproduction. However, due to its low immunogenicity, it is necessary to associate the GnRH with a carrier molecule capable of stimulating the immune system such as, for example, the B subunit of Escherichia coli heat-labile enterotoxin (LTB). The present study aimed to evaluate the immunocontraceptive potential of two LTB/GnRH chimeras in male BALB/c mice. Mice were randomly divided into eight experimental groups. The LTB/GnRH-P group received the chimera expressed in P. pastoris. The LTB/GnRH-P/A group received the chimera expressed in P. pastoris adsorbed in oil adjuvant. The LTB/GnRH-E group received the chimera expressed in E. coli. The LTB/GnRH-E/A group received the chimera expressed in E. coli adsorbed in oil adjuvant. The Control and Control/A groups did not receive vaccine antigen. The Commercial vaccine group received an anti-GnRH commercial vaccine used in cattle. The humoral immune response was evaluated by indirect ELISA and the immunocontraceptive potential was assessed through the quantification of serum testosterone and the histological analysis of animal’s gonads. The groups that received LTB/GnRH antigens (25 μg per vaccine) presented total IgG levels significantly higher when compared to the control groups, showing that both antigens are immunogenic. The LTB/GnRH-P and LTB/GnRH-P/A groups showed higher absorbances at days 28 (1,11 ± 0,09) and 42 (1,44 ± 0,04), respectively. Furthermore, the LTB/GnRH-P/A group presented testosterone levels significantly lower to the control from day 28 (192 ng/dl ± 254,55). The LTB/GnRH-E and LTB/GnRH-E/A groups also obtained the highest antibody levels at days 28 (0,33 ± 0,005) and 42 (1,44 ± 0,08), respectively. The LTB/GnRH-E/A group presented testosterone levels significantly lower to the control from day 28 (<12 ng/dl ± 0). The results from histology showed that both antigens cause changes in spermatogenesis, wherein the antigen expressed in E. coli was associated with major changes in gonads. The present study showed that chimeras produced through the merge of LTB with a single GnRH molecule is capable to induce the generation of humoral immune response, block of the endocrine functions related to reproduction, and tissue alterations in the gonads of male mice.