Glutathione and IGF-1 in bovine seminal cryopreservation: oxidative stress response and pregnancy rate / [Glutationa e IGF-1 na criopreservação seminal bovina: resposta do estresse oxidativo e taxa de gestação]

The objective of this study was to evaluate the rate of conception, metabolic, and structural conditions of cryopreserved bovine sperm cells, plus extender with IGF-1 and glutathione (GSH). 12 ejaculations of Nelore bulls were used, submitted to treatments: control, gSH (2mM/mL), IGF-1 (100ng/mL) and gSH (1mM/mL) + IGF-1 (50ng/mL). After cryopreservation and thawing the semen passed the fast thermo resistance test (TTR), plasma membrane and acrosomal integrity (PIAI), mitochondrial membrane potential (AP), oxidative stress, and conception rate. Tukey test was used for the statistical analysis of the parametric variables and the Friedman test for nonparametric. The gestation percentage was compared by the Chi-square test. There was no statistical difference (P<0.05) between treatments for the TTRr variable. Otherwise in the oxidative stress evaluated with the CellROX probe was noted that the IGF-1 showed the highest number of reactive cells (P<0.05). The PIAI, AP and gestation rate showed no difference among treatments (P>0.05), with an average of conceptions of 36.58%. It is concluded that IGF-1, gSH and their association did not cause changes in sperm motility, mitochondrial potential, plasma and acrosomal membrane integrity. IGF-1 increased oxidative stress, however, there was no difference in the gestation rate among the treatments.(AU)

Objetivou-se avaliar a taxa de concepção, as condições metabólicas e estrutural das células espermáticas bovinas criopreservadas, acrescidas de diluidores com fator de crescimento semelhante à insulina do tipo 1(IGF-1) e glutationa (GSH). Foram utilizados 12 ejaculados de touros da raça Nelore, submetidos aos tratamentos: controle, gSH (2mM/mL), IGF-1 (100ng/mL) e gSH (1mM/mL) + IGF-1 (50ng/mL). Após a criopreservação e descongelação, o sêmen passou pelos testes de termorresistência rápida (TTRr), integridade de membrana plasmática e acrossomal (PIAI), alto potencial mitocondrial (AP), estresse oxidativo e taxa de concepção. Utilizou-se o teste de Tukey para as análises estatísticas das variáveis paramétricas e o teste de Friedman para as não paramétricas, com significância de 5%. A percentagem de gestação foi comparada pelo teste do qui-quadrado. Não hove diferença estatística (P<0,05) entre os tratamentos para a variável TTRr. Já no estresse oxidativo avaliado com a sonda CellROX, observou-se que o IGF-1 apresentou maior quantidade de células reativas (P<0,05), 36,38± 24,10. A PIAI, o AP e a taxa de gestação não apresentaram diferença entre tratamentos (P>0,05), com média de concepções de 36,58%. Conclui-se que o IGF-1, a gSH e a sua associação não causaram mudanças na motilidade espermática, no potencial mitocondrial, na integridade da membrana plasmática e acrossomal. O IGF-1 aumentou o estresse oxidativo, porém sem diferença na taxa de gestação entre os tratamentos.(AU)

Does supplementation of vitamin C, reduced glutathione or their association in semen extender reduce oxidative stress in bovine frozen semen? / A suplementação de vitamina C, glutationa reduzida ou sua associação no diluidor de sêmen reduz o estresse oxidativo no sêmen congelado bovino?

The aim of this study was to evaluate the addition of vitamin C, reduced glutathione and the association thereof to the bovine semen cryopreservation extender. The ejaculate from nine bulls were divided into four fractions, each corresponding to a treatment, namely: control group-semen diluted with Tris-yolk extender; vitamin C group-semen diluted in Tris-yolk extender supplemented with vitamin C (2.5mmol/mL); glutathione group-semen diluted in Tris-yolk extender supplemented with reduced glutathione (2.5mmol/mL) and associated group-semen diluted in Tris-yolk extender supplemented with vitamin C (1.25mmol/mL) and reduced glutathione (1.25mmol/mL). Afterwards, the semen was packed into French straws and submitted to cryopreservation using automated equipment. After cryopreservation, the semen was thawed and evaluated considering sperm motility, morphology, plasma membrane, acrosome, mitochondrial potential and oxidative stress, as well as the thermo resistance test. Extender's supplementation with the association of vitamin C and reduced glutathione showed benefic effects on sperm motility and preservation of plasma and acrosomal membranes during semen cryopreservation, being also the group that showed higher values of reactive oxygen species. Thus, the association of both antioxidants contributed to the preservation of sperm cells in every analyzed characteristic, suggesting its use on bovine semen cryopreservation.(AU)

O objetivo deste estudo foi avaliar a adição de vitamina C, glutationa reduzida e sua associação ao diluidor de criopreservação de sêmen bovino. O ejaculado de nove touros foi dividido em quatro frações, cada uma correspondendo a um tratamento, a saber: grupo controle - sêmen diluído em Tris-gema; grupo vitamina C - sêmen diluído em Tris-gema, suplementado com vitamina C (2,5mmol/mL); grupo glutationa - sêmen diluído em Tris-gema, suplementado com glutationa reduzida (2,5mmol/mL) e grupo sêmen associado - diluído em Tris-gema, suplementado com vitamina C (1,25mmol/mL) e glutationa reduzida (1,25mmol/mL ). Posteriormente, o sêmen foi envasado em palhetas francesas e submetido à criopreservação por meio de equipamento automatizado. Após a criopreservação, o sêmen foi descongelado e avaliado quanto à motilidade espermática, à morfologia, à membrana plasmática, ao acrossoma, ao potencial mitocondrial e ao estresse oxidativo, bem como pelo teste de resistência térmica. A suplementação de extensor com a associação de vitamina C e glutationa reduzida mostrou efeitos benéficos sobre a motilidade espermática e a preservação das membranas plasmática e acrossomal durante a criopreservação de sêmen, sendo também o grupo que apresentou maiores valores de espécies reativas de oxigênio. Assim, a associação de ambos os antioxidantes contribuiu para a preservação dos espermatozóides em todas as características analisadas, sugerindo sua utilização na criopreservação de sêmen bovino.(AU)

Supplementation with long-acting progesterone in early diestrus in beef cattle: II. Relationships between follicle growth dynamics and luteolysis.

The aims were to characterize follicular dynamics in response to supplemental progesterone (P4) and to investigate the relationships between follicular growth and onset of luteolysis in P4-treated cows, submitted or not to artificial insemination (AI). Nonsuckled beef cows detected in estrus were assigned to receive AI or to remain non-AI. Three days after ovulation (ie, D3), AI cows were injected with 150 mg of long-acting P4 (AI + injectable P4 formulation [iP4]; n = 22), and the non-AI cows were assigned to receive 150 mg iP4 (n = 19) or saline (control, n = 19). Between D3 and D21, growth dynamics of the dominant follicles (DFs) was monitored by ultrasonography. Plasma P4 concentrations were measured every other day from D9 to D19. Pregnancy status (ie, P: pregnant and NP: nonpregnant) was examined by ultrasound on D28 to D32. Injectable P4 formulation supplementation decreased average maximum diameter of first-wave DF (DF1). Neither day of emergence of DF2 or DF3 nor the proportion of two- or three-wave cycles were altered by supplemental P4. Daily mean diameter of DF2 and DF3 was also similar between control and iP4 groups. Consistently, daily mean diameter of DF1 in iP4-treated cows was smaller for cows that underwent luteolysis by D15 compared to a later onset. Progesterone concentrations between D9 and D19 decreased earliest in the iP4 group, latest in the control group and was intermediate for the NP-AI + iP4 group. In addition, three-wave cycles presented a delayed decrease on plasma P4 concentrations than two-wave cycles. Further analysis revealed that on two-wave cycles, P4 concentrations on D15 were lowest in the iP4 and NP-AI + iP4 animals compared to the control and P-AI + iP4 groups. Conversely, for three-wave cycles, on D15, P-AI + iP4, NP-AI + iP4, and controls had greater P4 concentrations than the iP4 group. In summary, our data indicate that impairment of first follicular growth was associated with P4-induced shortened luteal lifespan (D14-D15) and that three-wave cycles after AI can be more supportive for pregnancy maintenance in P4-treated cows. We speculate that such conditions play a critical role in the embryonic ability to inhibit iP4-induced early luteolysis reported in part I of this series.

Supplementation with long-acting progesterone in early diestrus in beef cattle: I. effect of artificial insemination on onset of luteolysis.

Progesterone (P4) supplementation in early diestrus advances changes in the endometrial transcriptome, stimulating embryonic development. However, it also induces early onset of luteolysis. Occurrence of luteolysis before D16 postmating can be detrimental to fertility. A potential counteracting role of the elongating conceptus on early luteolysis is understood poorly. The aim of the study was to evaluate the effect of artificial insemination (AI; ie, pregnancy) on the temporal dynamics of luteolysis of cows supplemented with P4. Nonsuckled beef cows were inseminated at 12 h after estrus (D0: ovulation) or were not inseminated (no-AI). On D3, the AI cows were assigned to receive a single dose of 150 mg of injectable long-acting P4 via intramuscular injection (AI + iP4; n = 23), and the no-AI cows were assigned to receive iP4 (iP4; n = 21) or saline (control, n = 22). Corpus luteum (CL) development and regression were determined by ultrasonography (US) between D3 and D21. Plasma P4 concentrations were measured on D3 and every other day from D9 to D21. Pregnancy status was determined by US (D28‒D32). iP4 supplementation reduced luteal development (D5-D10) compared to the control group and increased incidence of luteolysis between D14 and D15. On D15, the proportion of cows that underwent luteolysis and plasma P4 concentrations differed between the iP4 group (47.6; 2.10 ± 0.47) and the control group (13.6; 4.40 ± 0.46) and was intermediate in the AI + iP4 group, respectively (26.1%; 3.70 ± 0.45 ng/mL; P < 0.05). The AI effects were due to the pregnant cows (n = 7). Considering nonpregnant cows only, the proportion of early luteolysis in the AI + iP4 group (37.5%) was similar to the iP4 group. Pregnancy was not established in cows having a shortened luteal lifespan. Indeed, interval to luteolysis in the AI + iP4 group (15.50 ± 0.66 d) was similar to the iP4 group (16.38 ± 0.46 d), but less than the control group (17.38 ± 0.40 d; P = 0.05). In conclusion, the effect of AI on extending luteal lifespan occurred exclusively in cows that maintained pregnancy.

Orquiepididimite em carneiro por Salmonella enterica sub-diarizonae: primeiro caso na América do Sul / Orchiepididymitis in ram by Salmonella enterica sub diarizonae: first case in South America

O objetivo deste artigo é relatar um caso de orquiepididimite associado com infecção por Salmonella enterica subespécie diarizonae em carneiro da raça Santa Inês de quatro anos de idade, vasectomizado. Ao exame clínico reprodutivo, o animal mostrou aumento severo do conteúdo escrotal, sendo o testículo direito maior do que o esquerdo e a cauda do epidídimo direita maior do que a esquerda. A consistência testicular, avaliada em escala de 1 a 5, foi 5 para o testículo direito e 2,5 para o esquerdo; o órgão apresentava-se muito sensível ao toque. Na ultrassonografia foram observadas estruturas anecoicas/hipoecoicas circulares na cauda do epidídimo, sugestivas de abscessos; alguns pontos hiperecogênicos no parênquima testicular, sugerindo lesões de calcificação; e todo o testículo direito rodeado por imagem hipoecoica, indicativa de edema. Uma das estruturas da cauda do epidídimo direita foi puncionada, encontrando-se exsudato purulento, o qual foi enviado para exame microbiológico, sendo isolada e identificada Salmonella enterica subespécie diarizonae. O carneiro foi submetido a orquiepididectomia, e o órgão foi caracterizado macroscopicamente por adesões fibrosas entre as camadas escrotais, coexistência de abscessos epididimários e degeneração testicular. A Salmonella enterica subespécie diarizonae deve ser considerada no diagnóstico diferencial de infecção genital em ovinos.

The objective of this manuscript was to report a case of orchiepididymitis associated with Salmonella enterica subespécie diarizonae infection in a vasectomized 4-year-old Santa Inês ram. In the clinical-reproductive examination, the animal showed a severe enlargement of the scrotal contents, being the right testicle larger than left, and the right epididymal cauda was higher than the left. The testicular consistency, evaluated in a scale from 1 to 5, was 5 to the right and 2.5 to the left, and the organ was very sensitive to the touch. In the ultrasound circular structures anechoic/hypoechoic in the epididymal cauda were observed, and in the parenchyma of testicles some points of hyperechogenic image, suggesting calcification lesions and the entire right testicle was surrounded by hypoechoic image, indicative of edema. One of those structures of the right epididymal cauda was aspirated and a purulent exsudate was found, which was sent to microbiological exam, was isolated and identified Salmonella enterica subespécie diarizonae. The ram was submitted to orchiepididectomy, and the organ was characterized macroscopically by fibrous adhesions between scrotum layers, coexistence of epididymal abscesses and testicular degeneration. The Salmonella enterica subspecie diarizonae must be taken into account in the differential diagnosis of ovine genital infections.

Effects of bovine sperm cryopreservation using different freezing techniques and cryoprotective agents on plasma, acrosomal and mitochondrial membranes.

The success of semen cryopreservation is influenced by several factors, such as freezing curves and cryoprotectants. These two factors are of special interest once they may lead to many important physical-chemical changes resulting in different degrees of damage in spermatozoa structure. This experiment was designed to compare the effect of bull semen cryopreservation using two freezing techniques: conventional (CT--cooling rate of -0.55 °C min(-1) and freezing rate of -19.1 °C min(-1) and automated (AT--cooling rate of -0.23 °C min(-1) and freezing rate of -15 °C min(-1)), performed with different curves, and with three cryoprotectants (glycerol, ethylene glycol and dimethyl formamide) on bovine sperm motility and integrity of plasma, acrosomal and mitochondrial membranes. These variables were simultaneously evaluated using the fluorescence probes propidium iodide, fluorescein-conjugated Pisum sativum agglutinin and MitoTracker Green FM. The effects of freezing techniques, as well as of different cryoprotectants were analysed by the analysis of variance. The means were compared by Fisher's test. There were no significant differences between freezing techniques (P > 0.05). Glycerol showed higher percentages of motility, vigour and integrity of plasma, acrosomal and mitochondrial membranes than other two cryoprotectants (P < 0.05). Ethylene glycol preserved higher motility and integrity of plasma and mitochondrial membranes than dimethyl formamide (P < 0.05). Sperm motility with glycerol was 30.67 ± 1.41% and 30.50 ± 1.06%, with ethylene glycol was 21.17 ± 1.66% and 21.67 ± 1.13% and with dimethyl formamide was 8.33 ± 0.65% and 9.17 ± 0.72% to CT and AT curves, respectively. The percentage of spermatozoa with simultaneously intact plasma membrane, intact acrosome and mitochondrial function (IPIAH) was 14.82 ± 1.49% (CT) and 15.83 ± 1.26% (AT) to glycerol, 9.20 ± 1.31% (CT) and 9.92 ± 1.29% (AT) to ethylene glycol 4.65 ± 0.93% (CT) and 5.17 ± 0.87% (AT) to dimethyl formamide. Glycerol provided the best results, although nearly 85% of spermatozoa showed some degree of injury in their membranes, suggesting that further studies are required to improve the results of cryopreservation of bovine semen.

Effects of discontinuous Percoll gradient centrifugation on the quality of bovine spermatozoa evaluated with computer-assisted semen analysis and fluorescent probes association.

The objective of this study was to evaluate the quality of bovine frozen-thawed sperm cells after Percoll gradient centrifugation. Frozen semen doses were obtained from six bulls of different breeds, including three taurine and three Zebu animals. Four ejaculates per bull were evaluated before and after discontinuous Percoll gradient centrifugation. Sperm motility was assessed by computer-assisted semen analysis and the integrity of the plasma and acrosomal membranes, as well as mitochondrial function, were evaluated using a combination of fluorescent probes propidium iodide, fluorescein isothiocyanate-conjugated Pisum sativum agglutinin and 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolcarbocyanine iodide. The procedure of Percoll gradient centrifugation increased the percentage of total and progressive sperm motility, beat frequency, rectilinear motility, linearity and rapidly moving cells. In addition, the percentage of cells with intact plasma membrane and mitochondrial membrane potential was increased in post-centrifugation samples. However, the percentage of sperm cells with intact acrosomal membrane was markedly reduced. The method used selected the motile cells with intact plasma membrane and higher mitochondrial functionality in frozen-thawed bull semen, but processing, centrifugation and/or the Percoll medium caused damage to the acrosomal membrane.

Addition of seminal plasma to post-thawing equine semen: what is the effect on sperm cell viability?

Effect of seminal plasma addition after thawing on viability or cryocapacitation is not definitively established. This experiment was performed to verify the effect of adding seminal plasma, autologous or homologous (from an animal with good semen freezability). Five ejaculates from each of four stallions with proven fertility were collected and cryopreserved. The semen was subsequently thawed and divided into the following three treatment groups: no seminal plasma addition after semen thawing (NOSP); the addition of homologous seminal plasma after semen thawing (HSP) and the addition of autologous seminal plasma after semen thawing (ASP). The addition of 20% of seminal plasma led to an increase in the cell population that simultaneously show plasma and acrosomal membrane integrity (p < 0.05). The addition of seminal plasma did not alter the total motility, the amount of cells with mitochondrial membrane potential or the sperm velocities (average path velocity, straight-line velocity and curvilinear velocity). However, the beat/cross-frequency, straightness and linearity were reduced in ASP and HSP groups (p < 0.05). Unexpectedly, the addition of homologous seminal plasma reduced the proportion of cells with progressive motility (p < 0.05) and the addition of autologous seminal plasma reduced the amplitude of the lateral head displacement (p < 0.05). Based on the increase in the cell populations that had the plasma and acrosomal membrane integrity simultaneously identified in this study, we proposed that the addition of seminal plasma (autologous or homologous) into post-thawed semen before insemination could increase semen fertility.

Simultaneous assessment of plasmatic, acrosomal, and mitochondrial membranes in ram sperm by fluorescent probes / Avaliação simultânea das membranas plasmática, acrossomal e mitocondrial de espermatozoides de carneiros por sondas fluorescentes

In this experiment, it was defined a protocol of fluorescent probes combination: propidium iodide (PI), fluorescein isothiocyanate-conjugated Pisum sativum agglutinin (FITC-PSA), and JC-1. For this purpose, four ejaculates from three different rams (n=12), all showing motility >80 percent and abnormal morphology <10 percent, were diluted in TALP medium and split into two aliquots. One of the aliquots was flash frozen and thawed in three continuous cycles, to induce damage in cellular membranes and to disturb mitochondrial function. Three treatments were prepared with the following fixed ratios of fresh semen:flash frozen semen: 0:100 (T0), 50:50 (T50), and 100:0 (T100). Samples were stained in the proposal protocol and evaluated by epifluorescence microscopy. For plasmatic membrane integrity, detected by PI probe, it was obtained the equation: v=1.09+0.86X (R²=0.98). The intact acrosome, verified by the FITC-PSA probe, produced the equation: v=2.76+0.92X (R²=0.98). The high mitochondrial membrane potential, marked in red-orange by JC-1, was estimated by the equation: v=1.90+0.90X (R²=0.98). The resulting linear equations demonstrate that this technique is efficient and practical for the simultaneous evaluations of the plasmatic, acrosomal, and mitochondrial membranes in ram spermatozoa.

Neste experimento, foi definida uma combinação de sondas fluorescentes: iodeto de propídio (PI), aglutinina de Pisum sativum conjugada ao isotiocionato de fluoresceína (FITC-PSA) e JC-1. Para esta proposta, quatro ejaculados de três carneiros (n=12), que apresentavam motilidade >80 por cento e alterações morfológicas <10 por cento, foram diluídos em meio TALP e divididos em duas alíquotas. Uma alíquota foi submetida a três ciclos de flash frozen e descongelação, para induzir danos nas membranas celulares e distúrbios na função mitocondrial. Três tratamentos foram preparados com as seguintes proporções preestabelecidas de sêmen fresco: sêmen submetido a flash frozen: 0:100 (T0), 50:50 (T50) e 100:0 (T100). As amostras foram coradas no protocolo proposto e avaliadas por microscopia de epifluorescência. Para integridade de membrana plasmática, detectada pela sonda PI, foi obtida a equação: v=1,09+0,86X (R²=0,98). O acrossomo intacto, verificado pela sonda FITC-PSA, produziu a equação: v=2,76+0,92X (R²=0,98). O alto potencial de membrana mitocondrial, marcada em vermelho-alaranjado pelo JC-1, foi estimado pela equação: v=1,90+0,90X (R²=0,98). As equações lineares resultantes demonstraram que a técnica é eficiente e prática para avaliação simultânea das membranas plasmática, acrossomal e mitocondrial em espermatozoides de carneiros.

Practical techniques for bovine sperm simultaneous fluorimetric assessment of plasma, acrosomal and mitochondrial membranes.

This experiment was performed to develop and validate practical techniques for simultaneous evaluation of the integrity of plasma and acrosomal membranes, as well as mitochondrial function in bovine spermatozoa using associations of fluorescent probes. Four protocols of fluorescent probes association were defined: protocol 1: propidium iodide (PI), fluorescein isothiocyanate-conjugated Pisum sativum agglutinin (FITC-PSA) and rhodamine 123; protocol 2: PI, FITC-PSA and MitoTracker Green FM (MITO); protocol 3: PI, Hoechst 33342 (H342), FITC-PSA and CMXRos; and protocol 4: PI, H342, FITC-PSA and JC-1. Three ejaculates from each of the four bulls (n = 12) were utilized, showing sperm motility >/=80% and abnormal morphology

Fluorescent stain method for the simultaneous determination of mitochondrial potential and integrity of plasma and acrosomal membranes in boar sperm.

The purpose of this study was to validate a technique for simultaneous evaluation of the plasma, acrosomal and mitochondrial membranes in boar spermatozoa, using an association of fluorescent probes: Propidium iodide (PI), fluorescein isothiocyanate-conjugated Pisum sativum agglutinin (FITC-PSA) and JC-1. Three ejaculates from each of four different boars, all showing motility >or=80% and abnormal morphology