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Comparative Genome Analysis of Infectious Human and Domestic Animal Coronaviruses Texte intégral
2023
Rajaei, Taraneh | Nikbakht Brujeni, Gholamreza | Frootan, Fateme | Mehrzad, Jalil | Houshmand, Pouya
BACKGROUND: Coronaviruses, which mainly cause gastrointestinal and respiratory infections, have been identified in various species. Among the extensive genomic data of disease-causing Coronaviruses in humans and animals, some similarities can be analyzed by in-silico methods. OBJECTIVES: In the present study, comparative genome analysis of medical and veterinary medicine Coronaviruses was performed to obtain more accurate information about the genetic similarities and differences of different members of this family.METHODS: The genomic sequences were retrieved from NCBI and Virus Pathogen Resource databases. Using the NCBI database blast algorithm, all sequences were aligned with the SARS-CoV-2 genome sequence, and similarity was obtained. Amino acid sequences of structural and non-structural proteins associated with coding regions (CDS) were aligned separately with the SARS-CoV-2, and their similarities were calculated. The 3D structure from each protein was compared with the corresponding protein in SARS-CoV-2, and Template Modeling Scores (TM-Score) were obtained. A phylogenetic tree of different species of the Coronaviridae family was drawn based on nucleotide and amino acid sequence data.RESULTS: Nonstructural coding gene sequences detected the highest interspecies similarities in nucleotide, amino acid sequence, and 3D structure (nsp12, nsp13, nsp14, and nsp16). The ORF1ab, encoding non-structural proteins, carries essential functions for viral replication.CONCLUSIONS: This study showed that the transcription complex is highly conserved among human and animal Coronaviruses. A comparison and analysis of the Coronaviridae transcription complex can be considered a key target for diagnosing, developing antiviral therapies, and designing vaccines.
Afficher plus [+] Moins [-]Frequency and Possible Determinants of Infections Caused by Beta-Hemolytic Streptococci of the Respiratory Tract in Horses with Clinical Signs in Northwestern Breeding Centers of Iran: A Cross-Sectional Survey Texte intégral
2023
Moghaddam, Sina | Lotfollahzadeh, Samad | Zahraei Salehi, Taghi | Hassanpour, Ali | Tavanaei Manesh, Hamid | Akbarein, Hesameddin
BACKGROUND: Respiratory pathogenic beta-hemolytic streptococci in horses, including Streptococcus equi subsp. equi, the causative agent of strangles disease, Streptococcus equi subsp. zooepidemicus is an important cause of respiratory disease and Streptococcus dysgalactiae subsp. equisimilis has been isolated from nasal swabs taken from horses with a history of respiratory disease.OBJECTIVES: The present study aimed to determine the frequency and risk factors of respiratory tract infections originating from beta-hemolytic streptococci in the provinces of West Azerbaijan, East Azerbaijan, and Ardabil.METHODS: During this study, 121 horses with clinical respiratory symptoms were sampled. After performing clinical examinations and recording clinical signs in special worksheets, sampling of the upper part of the respiratory tract was performed using nasopharyngeal swabs. The samples were sent to the laboratory in a standard transfer medium with cold chain.RESULTS: In this study, out of 121 samples collected from horse breeding clubs from 10 different regions of northwestern Iran, 51 were negative for beta-hemolytic streptococci while the results were positive for the other 70 samples (P<0.001). Regarding the positive samples for beta-hemolytic streptococci, the results of differential cultures were as follows: eight cases of Streptococcus equi subsp. equi, 57 cases of Streptococcus equi subsp. zooepidemicus, and five cases of Streptococcus dysgalactiae subsp. equisimilis. There was no significant relationship between the frequency of beta-hemolytic infections with variables of gender, race, and geographical area (P>0.05). Meanwhile, the statistical test showed a significant relationship between the frequency of infection with these bacteria and the variable of clinical symptoms (P<0.001). Moreover, the frequency of beta-hemolytic streptococcal infections was significantly associated with age (P<0.05).CONCLUSIONS: The results herein suggested that the bacterial cause of the majority of respiratory infections in infected and sampled horses in the provinces of West Azerbaijan, East Azerbaijan, and Ardabil at the time of sampling was Streptococcus equi subsp. zooepidemicus and that this organism is a potential pathogen for respiratory diseases in horses in these provinces.
Afficher plus [+] Moins [-]The Effect of Curcumin on the Structure of Mouse Ovary After Treatment With Goserelin and Cyclophosphamide Texte intégral
2023
Azarmi, Sareh | Talebkhan Garoussi, Massoud | Tajik, Parviz | Hosseini Pajooh, Khosro | Sasani, Farhang | Jahanroshan, Navid
BACKGROUND: Protection from reproductive damage is essential in chemotherapy medicines for cancer patients.OBJECTIVES: This study aims to examine the effect of curcumin on the structure of the ovary of mice after treatment with goserelin and cyclophosphamide.METHODS: One hundred and ten BALB/C mice with 3 regular consecutive periods of the estrous cycle were divided into 11 groups of 10 each. No medicine was used in the control group. The treatment groups were as follows: 1) cyclophosphamide, 2 to 5) cyclophosphamide with curcumin with a dose of 100, 200, 300, and 400 mg/kg, respectively, 6) goserelin, 7 to 10) goserelin together with curcumin with a dose 100, 200, 300, 400 mg/kg, respectively. The luteinizing hormone (LH) and follicle-stimulating hormone (FSH) of serums were evaluated using ELISA. Morphologic and morphometric of ovaries were assessed.RESULTS: The total number of follicles, primary, secondary, periantral, and antral follicles, in the goserelin and cyclophosphamide group, was significantly reduced compared with the control group (P<0.05). Cyclophosphamide and goserelin with different doses of curcumin showed a significant increase in the total number of follicles, primary, periantral, and antral follicles compared to the group treated with cyclophosphamide and goserelin alone (P<0.05). Curcumin (200, 300, and 400 mg/kg) and cyclophosphamide, compared to the cyclophosphamide group, significantly increased the quality of zona pellucida (P<0.05). Cyclophosphamide and goserelin caused a significant decrease in FSH and LH (P<0.05). Cyclophosphamide with different doses of curcumin showed a significant increase in LH compared to the group treated with cyclophosphamide alone (P<0.05). Goserelin with a 400 mg/kg curcumin dose significantly increased LH compared to goserelin alone (P<0.05). The amount of FSH in the cyclophosphamide groups with curcumin increased compared considerably to cyclophosphamide alone (P<0.05). The groups of goserelin with curcumin showed a significant increase in FSH compared to those of goserelin alone (P<0.05).CONCLUSIONS: Curcumin can protect the reproductive system of mice from the damage caused by the administration of cyclophosphamide and goserelin.
Afficher plus [+] Moins [-]A Comparison Survey on Native and Denaturation Conditions for Solubilization and Purification of Toxocara canis C-type Lectin Recombinant Protein Texte intégral
2023
Malekzadeh, Parmida | Hosseini, Seyed Hossein | Jalousian, Fateme | Akrami, Mohammad | Amini Nia, Narges
BACKGROUND: Toxocara canis C-type lectin (T. canis-CTL) is the main protein part of the secretory-excretory product secreted by Toxocara canis infective larvae. T. canis-CTL can stimulate immune response-mediated regulatory T lymphocytes, increase the FOXP3+ cells population, and reduce severe inflammatory responses. T. canis-CTL is a promising candidate for immune modulation in some autoimmune diseases, deserving further investigation.OBJECTIVES: The current research aimed to purify the recombinant T. canis-CTL under denaturation and native condition to increase exploration and maintain biological activity.METHODS: The expression vector, pET32a was constructed with the partial sequence 660bp of T. canis-CTL and expressed in E. coli BL21 (DE3). T. canis-CTL protein expression was induced by IPTG (1 mM) at 37°C after 6 h. In this study, different buffers were used for cell explosion and recombinant protein solubilization, including lysis buffer with urea (8 M, pH=8) and lysozyme enzyme as well as lysis buffer with Imidazole (0.01 M) and lysozyme enzyme, and previous buffers in addition to sonication. The effect of these buffers was evaluated in bacterial cells explosion, using Gram-staining and microscopic examination. Recombinant T. canis-CTL protein was extracted and purified under denaturation and native condition using Ni-NTA affinity chromatography by agarose and sepharose resin. A New Zealand male rabbit was immunized with the recombinant protein to evaluate the bioactivity of the protein. RESULTS: Lysis buffer with urea (8 M, pH=8) and lysozyme enzyme, in addition to sonication, provided acceptable results, and an additional amount of recombinant T. canis-CTL protein was secreted in the buffer. Protein purification under denaturation conditions with Ni-NTA agarose affinity chromatography also provides further recombinant protein. Most of the induction of recombinant T. canis-CTL with 41 KDa molecular weight was collected 6 h after induction at 37°C. Dot-blot results illustrate the brown dot, which showed a 1:500 titer of specific IgG polyclonal antibody has developed in the sera of rabbits immunized with T. canis-CTL recombinant protein.CONCLUSIONS: The denaturation condition did not affect the biological activity of the T. canis-CTL recombinant protein and can recover a further amount of recombinant proteins.
Afficher plus [+] Moins [-]Measuring Mercury Level in Edible Tissue of Farmed Whiteleg Shrimp (Litopenaeus vannamei) in Bushehr Province of Iran Using Cold Vapor Method Texte intégral
2023
Sadeghi Limanjoob, Reza | Zargar, Ashkan | Taheri Mirghaed, Ali
BACKGROUND: Many toxic elements enter human food in different ways by various industries which can put people's lives in danger. Heavy metals can be rarely removed from the body after absorption and deposition in tissues, which can lead to diseases and complications in the body. Mercury is one of the heavy metals that can posion people after consumption of contaminated seafood. The measurement of pollutants such as mercury that present in aquatic animals and environment is one of challenges for humans.OBJECTIVES: This study aims to measure the amount of mercury accumulation in the edible tissue of whiteleg shrimp (Litopenaeus vannamei) found in farms of Bushehr Province in Iran.METHODS: In this research, 70 whiteleg shrimps were collected during four sampling stages in July, August, September and October for two consecutive years. Total mercury level was measured by the cold vapor method.RESULTS: The level of mercury was 0-0.009 mg/kg of body weight, while the recommended limit for mercury is 0.1 mg/kg according to the WHO. The microscopic study on tissue sections did not show any histopathological changes.CONCLUSIONS: The mercury level in the edible tissue of whiteleg shrimps in Bushehr province is much lower than the recommded level and does not pose any danger to residents and consumers.
Afficher plus [+] Moins [-]Effect of Saponin Encapsulated by Ferritin Nanoparticles on Fetal Lung Development in Female Mice with Streptococcus pneumonia Texte intégral
2023
Safdarpour, Saba | Eftekhari, Zohre | Eidi, Akram | Doroud, Delaram
BACKGROUND: The effect of nanoherbal substances in the treatment of infectious diseases before mating or during pregnancy must be evaluated. Saponin has adverse effects on a pregnant mother and her fetal through complex mechanisms.OBJECTIVES: This study aims to investigate the toxic effects of saponin encapsulated by ferritin nanoparticles (Nanosaponin) on fetal lung development in female mice with Streptococcus pneumonia.METHODS: Extraction of crude saponin from licorice roots was done by the powder heating and using 20 % ethanol and diethyl ether. Then, n-butanol and 5 % sodium chloride solution were added to the aqueous layer. The mice were divided into five groups of 10 including control, pneumonia, pneumonia treated with ferritin, pneumonia treated with saponin, and pneumonia treated with nanosaponin. Then, two groups of untreated pregnant pneumonia and pregnant pneumonia treated with nanosaponin were separated. In this study, tumor necrosis factor alpha (IFN-γ), heparin-binding epidermal growth factor-like growth factor (HB-EGF), Methyl-CpG binding domain 2 (MBD-2), and kruppel like factor 2 (KLF-2) genes were evaluated in the maternal lungs, and TNF-α level was evaluated using ELISA method in the fetal lungs. Maternal tissue, uterus tissue, and fetal lung were examined by hematoxylin and eosin staining, and maternal body tissue was examined by trichromason staining and Oxidative stress parameters were investigated.RESULTS: Nano saponin decreased the expression of IFN-γ (P<0.05) (P<0.01), MBD-2 (P<0.05) and HB-EGF genes, KLF-2 protein level and TNF-α levels in fetal lung.The thickness of uterine myometrium and blood flow of endometrium increased the number of live embryos and the rate of successful pregnancy. In addition, Nano saponin effectively improved the oxidative stress response in the fetus without any harmful effect on the mother's liver tissue.CONCLUSIONS: The nanosaponin has no toxic effects on the sudy organs of the mother and fetus. It has therapeutic effects on the fetal lung development process after the infection of mother with Streptococcus pneumonia.
Afficher plus [+] Moins [-]Design and Molecular Docking Study of Recombinant Chimera Protein HBHA-Omp28 for Developing an Efficient Vaccine Against Salmonella typhimurium Texte intégral
2023
Abolvafaei, Seyedeh Zahra | Shams, Nemat | Forouharmehr, Ali | Jaydari, Amin | Nazifi, Narges
BACKGROUND: Salmonellosis is a dangerous disease that can threaten the health of humans and animals. This disease can lead to economic losses annually; therefore, many studies have been conducted to prevent this disease.OBJECTIVES: The current study aims to design a recombinant chimera protein HBHA-Omp28 as a vaccine against Salmonella typhimurium.METHODS: The nucleotide and amino acid sequences of Omp28 and HBHA proteins were first extracted from the NCBI database. Then, the recombinant chimera of HBHA-Omp28 was bioinformatically assembled using a rigid linker. Epitope prediction of T and B cells, antigenicity, allergenicity, and physicochemical features assessments of HBHA-Omp28 were done using Immune Epitope Database (IEDB), ABCpred, VaxiJen, AllerTOP and ProtParam online servers, respectively. To assess the secondary and tertiary structures, the Self-Optimized Prediction Method with Alignment (SOPMA) and the Iterative Threading ASSEmbly Refinement (I-TASSER) server were used, respectively. Molecular docking between recombinant chimera and TLR4/MD2 receptor was assessed by ClusPro server. Finally, after codon optimization of nucleotide sequence of recombinant chimera to express in Escherichia Coli k-12 strain, the cloning of recombinant chimera in pET21-a (+) vector was examined.RESULTS: The designed recombinant chimera was classified as an antigenic and non-allergenic protein with molecular weight of 34.19 kDa. According to the results of molecular docking study, the HBHA-Omp28 protein was able to bind to TLR4/MD2 receptor using 9 hydrogen bonds. The results of cloning study demonstrated that HBHA-Omp28 successfully cloned into pET21-a (+).CONCLUSIONS: The designed recombinant chimera can be an appropriate vaccine against salmonella bacteria.
Afficher plus [+] Moins [-]Energy Status, Body Condition, and level of Inflammatory Markers in Pregnant Ewes in the Transition Period Texte intégral
2023
Nemati Mazrae, Mahla | Anassori, Ehsan | Ramin, Ali-Goli
BACKGROUND: Body condition and its relationship with inflammatory indicators in the transition period of ewes can be used as a key to prevent the occurrence of metabolic complications in this period.OBJECTIVES: This study aims to determine the levels of inflammatory markers and their relationship with body condition and energy status in the transitional period in Makuei ewes.METHODS: This study was performed on 45 female peri-parturient Makuie ewes aged 3-5 years with 2-4 breeding lambs. Blood samples from the jugular vein were prepared in three periods, 21 days before delivery, baseline (time zero), and 21 days after delivery.RESULTS: The mean glucose and cholesterol concentrations were not significantly different between the groups with low, moderate, and high body conditions. Non-esterified fatty acids (NEFA) and β-hydroxybutyrate (BHB) concentrations were significantly higher in groups with lower and higher body condition scores (BCS) than in the normal group. There was a significant positive correlation between energy-related indices (NEFA, BHB) and the BCS of the pregnant and lactating ewes. The concentration of fibrinogen, sialic acid, and blood ceruloplasmin increased in the first three weeks and decreased after delivery. These indices significantly increased in relatively obese and lean groups than in the normal group during the study. The correlation of BHB and NEFA with sialic acid, ceruloplasmin, and fibrinogen was also reported in the study groups in the pre- and post-partum periods.CONCLUSIONS: Ewes with normal BCS (2.75-3.25) have a good energy status. Low levels of NEFA in ewes indicate that the mobility of fats is low, and the inflammation process is lower in the transition period of these animals. Furthermore, low BCS can be a predisposing factor for inflammation in ewes during the pre-partum period. This effect may be due to the increased metabolic requirements and compromised immune function associated with negative energy balance in the transition period of ewes.
Afficher plus [+] Moins [-]Efeito da mastite subclínica bovina sobre a produção de leite e desempenho econômico de fazendas leiteiras brasileiras | Effect of bovine subclinical mastitis on milk production and economic performance of Brazilian dairy farms Texte intégral
2023
Gonçalves, Juliano Leonel | Freu, Gustavo | Garcia, Breno Luís Nery | Barcelos, Melina Melo | Alves, Bruna Gomes | Leite, Renata de Freitas | Monteiro, Camylla Pedrosa | Martins, Cristian Marlon de Magalhães Rodrigues | Tomazi, Tiago | Hogeveen, Henk | Santos, Marcos Veiga dos | Goncalves , Juliano Leonel | Freu, Gustavo | Garcia, Breno Luís Nery | Barcelos, Melina Melo | Alves, Bruna Gomes | Leite, Renata de Freitas | Monteiro, Camylla Pedrosa | Martins, Cristian Marlon de Magalhães Rodrigues | Tomazi, Tiago | Hogeveen, Henk | Santos, Marcos Veiga dos
Efeito da mastite subclínica bovina sobre a produção de leite e desempenho econômico de fazendas leiteiras brasileiras | Effect of bovine subclinical mastitis on milk production and economic performance of Brazilian dairy farms Texte intégral
2023
Gonçalves, Juliano Leonel | Freu, Gustavo | Garcia, Breno Luís Nery | Barcelos, Melina Melo | Alves, Bruna Gomes | Leite, Renata de Freitas | Monteiro, Camylla Pedrosa | Martins, Cristian Marlon de Magalhães Rodrigues | Tomazi, Tiago | Hogeveen, Henk | Santos, Marcos Veiga dos | Goncalves , Juliano Leonel | Freu, Gustavo | Garcia, Breno Luís Nery | Barcelos, Melina Melo | Alves, Bruna Gomes | Leite, Renata de Freitas | Monteiro, Camylla Pedrosa | Martins, Cristian Marlon de Magalhães Rodrigues | Tomazi, Tiago | Hogeveen, Henk | Santos, Marcos Veiga dos
O objetivo deste artigo de revisão foi compilar os principais resultados obtidos em estudos brasileiros publicados em periódicos indexados, relacionados ao efeito da mastite subclínica (MS) sobre a produção e a rentabilidade de rebanhos leiteiros. Para isso, foram consideradas duas abordagens: (i) diagnóstico da mastite [com base na contagem de células somáticas (CCS) e na cultura microbiológica] e, (ii) estratégia de amostragem do leite (quartos mamários, amostras compostas de vacas e do tanque de rebanhos). A MS é a forma mais frequente de mastite em fazendas leiteiras, mas nem sempre seu impacto é compreendido adequadamente. A ausência de alterações visuais do leite, nos quartos mamários e/ou sistêmicas nas vacas acometidas dificulta o diagnóstico da MS, diminuindo a percepção das perdas e, consequentemente, levando os produtores a subestimarem os impactos na produção de leite e na rentabilidade dos rebanhos. O impacto da MS sobre a produção de leite e o desempenho econômico das fazendas leiteiras depende do patógeno causador da doença, do estágio da lactação e do número de parições das vacas. Assim, a estimativa das perdas causadas pela MS sobre produção de leite e o desempenho econômico das fazendas leiteiras pode ser usada para a tomada de decisões de implementação de medidas de controle da MS. De modo geral, o controle da MS requer a implantação de medidas especificas para cada rebanho, de acordo com o período em que há maior frequência de casos, o perfil de transmissão da doença e tipo de agente envolvido nos casos de mastite. Por isso, o monitoramento do rebanho pelo uso da CCS das vacas do rebanho, diagnóstico microbiológico de agentes causadores de MS, o uso de protocolos de secagem eficientes e medidas adicionais de manejo, são essenciais para o controle da mastite, qualidade do leite e desempenho econômico de fazendas leiteiras. | This review summarized the significant results from Brazilian studies published in peer-reviewed scientific papers about the effect of bovine subclinical mastitis (SM) on economic performance and milk production. Different approaches were considered for (i) disease detection (indirect measurement of somatic cell count (SCC) and directly using microbiological culture) and (ii) milk sampling strategy (mammary quarters, composite cow samples, and bulk milk tank). Globally, bovine mastitis is the most common disease of dairy herds, and the subclinical presentation is the most frequent. Dairy farmers usually underestimate the economic losses associated with SM because no visual changes in milk and quarters, udder, and systemic symptoms are observed. SM reduces milk yield and quality, reducing dairy herds’ profitability. The estimation of losses depends on the causative pathogen, the lactation stage, and the parity of affected cows. Thus, estimating the economic caused by SM in milk production and economic performance in dairy herds can be used to decide which mastitis control strategies to adopt. Mastitis control involves adopting specific measures associated with the characteristics of each herd, the period of the highest frequency of cases, the transmission form, and the profile of the pathogens involved in cases of intramammary infection. Thus, using individual SCC, the microbiological identification of pathogens causing SM, adopting efficient drying-off protocols, and other management practices are essential for mastitis control, improved milk quality, and greater profitability of dairy herds.
Afficher plus [+] Moins [-]Effect of bovine subclinical mastitis on milk production and economic performance of Brazilian dairy farms Texte intégral
2023
Goncalves, Juliano L. | Freu, Gustavo | Garcia, Breno L.N. | Barcelos, Melina M. | Alves, Bruna G. | de Freitas Leite, Renata | Pedrosa Monteiro, Camylla | Martins, M. | Tomazi, Tiago | Hogeveen, Henk | Veiga dos Santos, Marcos
This review summarized the significant results from Brazilian studies published in peer-reviewed scientific papers about the effect of bovine subclinical mastitis (SM) on economic performance and milk production. Different approaches were considered for (i) disease detection (indirect measurement of somatic cell count (SCC) and directly using microbiological culture) and (ii) milk sampling strategy (mammary quarters, composite cow samples, and bulk milk tank). Globally, bovine mastitis is the most common disease of dairy herds, and the subclinical presentation is the most frequent. Dairy farmers usually underestimate the economic losses associated with SM because no visual changes in milk and quarters, udder, and systemic symptoms are observed. SM reduces milk yield and quality, reducing dairy herds’ profitability. The estimation of losses depends on the causative pathogen, the lactation stage, and the parity of affected cows. Thus, estimating the economic caused by SM in milk production and economic performance in dairy herds can be used to decide which mastitis control strategies to adopt. Mastitis control involves adopting specific measures associated with the characteristics of each herd, the period of the highest frequency of cases, the transmission form, and the profile of the pathogens involved in cases of intramammary infection. Thus, using individual SCC, the microbiological identification of pathogens causing SM, adopting efficient drying-off protocols, and other management practices are essential for mastitis control, improved milk quality, and greater profitability of dairy herds.
Afficher plus [+] Moins [-]Motivação e desempenho sexual em ratos com e sem experiência sexual tratados com ivermectina: um estudo da vocalização ultrassônica | Sexual motivation and performance in sexual naïve and experienced rats treated with ivermectin: an ultrasonic vocalization study Texte intégral
2023
Rodrigues, Paula da Silva | Sampaio, Ana Claudia Silva | Silva, Éricka Patrícia da | Suffredini, Ivana Barbosa | Bondan, Eduardo Fernandes | Bernardi, Maria Martha | Kirsten, Thiago Berti | Rodrigues, Paula da Silva | Sampaio, Ana Claudia Silva | Silva, Éricka Patrícia da | Suffredini, Ivana Barbosa | Bondan, Eduardo Fernandes | Bernardi, Maria Martha | Kirsten, Thiago Berti
Em mamíferos, a ivermectina (IVM) atua como agonista do receptor GABAA e estimula a liberação de GABA. Estudos anteriores mostraram que a IVM reduz o desempenho sexual, prejudicando a latência para a primeira monta e intromissão. Esses parâmetros são geralmente considerados parâmetros motivacionais do comportamento sexual. Por outro lado, a IVM aumenta a atividade GABAérgica levando à incoordenação motora. Assim, é possível que a IVM afete o desempenho sexual devido a um impedimento motor. O presente estudo analisou a vocalização ultrassônica em ratos para verificar se a IVM prejudica o comportamento sexual via mecanismos motivacionais ou comprometimento motor. Uma vez que a experiência sexual atenua o comprometimento do desempenho motor, também foram estudados ratos com experiência sexual. Ratos sexualmente inexperientes e experientes foram administrados com uma dose terapêutica de IVM ou solução salina IVM. Os ratos foram expostos a fêmeas receptivas e foi avaliada a latência para a primeira monta, seguida do teste de vocalização ultrassônica (USV) de 50 kHz. O tratamento com IVM em ratos inexperientes aumentou a latência para a primeira monta em relação a ratos inexperientes tratados com solução salina, enquanto não foram observadas diferenças entre ratos experientes tratados com IVM e solução salina. Em ratos inexperientes tratados com IVM ocorreu redução da frequência e total de USVs, bem como aumento do tempo médio de USVs em relação aos ratos sem experiência. Ratos experientes tratados com IVM não mostraram diferenças na frequência, média e máxima das USVs em relação aos ratos experientes tratados com solução salina; no entanto, observou-se aumento no total de USVs e na frequência dominante de USVS em ratos experientes tratados com IVM comparados aos experientes tratados com solução salina. Observou-se correlação negativa e positiva entre a latência para a primeira monta e USVs nos grupos sem e com experiência tratados com IVM, respectivamente. Assim, propomos que a IVM aumentou a motivação sexual de ratos expostos a uma fêmea em estro com base em USVs, apesar de apresentar aumento na latência para a primeira monta. O aumento da latência para a primeira monta foi atribuída à incoordenação motora, conforme observado anteriormente e proposto por nosso grupo. | In mammals, ivermectin acts as a GABAA receptor agonist and stimulates GABA release. Previous studies showed that ivermectin (IVM) reduces sexual performance, impairing the latency to the first mount and intromission. These parameters are usually considered motivational parameters of sexual behavior. However, IVM increases GABAergic activity leading to motor incoordination. Thus, it is reasonable to propose that IVM affects sexual performance via motor incoordination pathways. The present study analyzed ultrasonic vocalization in rats to verify whether IVM impairs sexual behavior via motivational mechanisms or motor impairment. Because sexual experience attenuates the impairment of motor performance, rats with sexual experience were also studied. Sexually naive and experienced rats were administered a therapeutic IVM dose and saline. The rats were exposed to receptive females, and the latency to the first mount was evaluated, followed by the 50-kHz USV test. IVM treatment in naïve rats increased the latency to first to mount relative to Saline naïve rats, while no differences were observed between saline and experienced rats. In naïve-IVM rats, a reduced frequency and total calls and increased mean time of calls occur relative to SAL-naïve rats. Experienced IVM rats did not show differences in the frequency, mean, and maximal calls close to Saline experienced rats. However, an increase in the total calls and the dominant frequency of calls were observed in IVM-experienced rats compared to Saline experienced rats. A negative and positive correlation occurred between the latency to the first mount and USVs in groups with and without ivermectin exposure. Hence, we propose that ivermectin increased the sexual motivation of rats exposed to a female in estrous based in USVs despite an increased latency to the first mount that occurred. The increased latency to the first mount resulted from motor incoordination, as previously observed and proposed by our group.
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