Asunto(s)

Asunto(s)

RESUMEN

Videolaryngoscopes are thought to improve glottic view and facilitate tracheal intubation compared with the Macintosh direct laryngoscope. However, we currently do not know which one would be the best choice in most patients undergoing anaesthesia. We designed this systematic review with network meta-analyses to rank the different videolaryngoscopes and the Macintosh direct laryngoscope. We conducted searches in PubMed and a further five databases on 11 January 2021. We included randomised clinical trials with patients aged ≥16 years, comparing different videolaryngoscopes, or videolaryngoscopes with the Macintosh direct laryngoscope for the outcomes: failed intubation; failed first intubation attempt; failed intubation within two attempts; difficult intubation; percentage of glottic opening seen; difficult laryngoscopy; and time needed for intubation. We assessed the quality of evidence according to GRADE recommendations and included 179 studies in the meta-analyses. The C-MAC and C-MAC D-Blade were top ranked for avoiding failed intubation, but we did not find statistically significant differences between any two distinct videolaryngoscopes for this outcome. Further, the C-MAC D-Blade performed significantly better than the C-MAC Macintosh blade for difficult laryngoscopy. We found statistically significant differences between the laryngoscopes for time to intubation, but these differences were not considered clinically relevant. The evidence was judged as of low or very low quality overall. In conclusion, different videolaryngoscopes have differential intubation performance and some may be currently preferred among the available devices. Furthermore, videolaryngoscopes and the Macintosh direct laryngoscope may be considered clinically equivalent for the time taken for tracheal intubation. However, despite the rankings from our analyses, the current available evidence is not sufficient to ensure significant superiority of one device or a small set of them over the others for our intubation-related outcomes.

Asunto(s)

RESUMEN

We examined the potential for voice sounds to predict a difficult airway as compared with prediction by the modified Mallampati test. A total of 453 patients scheduled for elective surgery under general anaesthesia with tracheal intubation were studied. Five phonemes were recorded and their formants analysed. Difficult laryngoscopy was defined as the Cormack-Lehane grade 3 or 4. Univariate and multivariate logistic regression were used to examine the association between some variables (mouth opening, sternomental distance, modified Mallampati and formants) and difficult laryngoscopy. Difficult laryngoscopy was reported in 29/453 (6.4%) patients. Among five regression models evaluated, the model achieving better performance to predict difficult laryngoscopy, after a variable selection criteria (stepwise, multivariate) and included a modified Mallampati classification (OR 2.920; 95%CI 1.992-4.279; p < 0.001), first formant of /i/(iF1) (OR 1.003; 95%CI 1.002-1.04; p < 0.001), and second formant of /i/(iF2) (OR 0.998; 95%CI 0.997-0.998; p < 0.001). The receiver operating curve for a regression model that included both formants and Mallampati showed an area under curve of 0.918, higher than formants alone (area under curve 0.761) and modified Mallampati alone (area under curve 0.874). Voice presented a significant association with difficult laryngoscopy during general anaesthesia showing a 76.1% probability of correctly classifying a randomly selected patient. (AU)

Asunto(s)

RESUMEN

We examined the potential for voice sounds to predict a difficult airway as compared with prediction by the modified Mallampati test. A total of 453 patients scheduled for elective surgery under general anaesthesia with tracheal intubation were studied. Five phonemes were recorded and their formants analysed. Difficult laryngoscopy was defined as the Cormack-Lehane grade 3 or 4. Univariate and multivariate logistic regression were used to examine the association between some variables (mouth opening, sternomental distance, modified Mallampati and formants) and difficult laryngoscopy. Difficult laryngoscopy was reported in 29/453 (6.4%) patients. Among five regression models evaluated, the model achieving better performance to predict difficult laryngoscopy, after a variable selection criteria (stepwise, multivariate) and included a modified Mallampati classification (OR 2.920; 95%CI 1.992-4.279; p < 0.001), first formant of /i/(iF1) (OR 1.003; 95%CI 1.002-1.04; p < 0.001), and second formant of /i/(iF2) (OR 0.998; 95%CI 0.997-0.998; p < 0.001). The receiver operating curve for a regression model that included both formants and Mallampati showed an area under curve of 0.918, higher than formants alone (area under curve 0.761) and modified Mallampati alone (area under curve 0.874). Voice presented a significant association with difficult laryngoscopy during general anaesthesia showing a 76.1% probability of correctly classifying a randomly selected patient.

Asunto(s)

RESUMEN

Recent evidence shows that chronic ethanol consumption increases endothelin (ET)-1 induced sustained contraction of trabecular smooth muscle cells of the corpora cavernosa in corpus cavernosum of rats by a mechanism that involves increased expression of ETA and ETB receptors. Our goal was to evaluate the effects of alcohol and diabetes and their relationship to miRNA-155, miRNA-199 and endothelin receptors in the corpus cavernosum and blood of rats submitted to the experimental model of diabetes mellitus and chronic alcoholism. Forty-eight male Wistar rats were divided into four groups: control (C), alcoholic (A), diabetic (D), and alcoholic-diabetic (AD). Samples of the corpus cavernosum were prepared to study the protein expression of endothelin receptors by immunohistochemistry and expression of miRNAs-155 and -199 in serum and the cavernous tissue. Immunostaining for endothelin receptors was markedly higher in the A, D, and AD groups than in the C group. Moreover, a significant hypoexpression of the miRNA-199 in the corpus cavernosum tissue from the AD group was observed, compared to the C group. When analyzing the microRNA profile in blood, a significant hypoexpression of miRNA-155 in the AD group was observed compared to the C group. The miRNA-199 analysis demonstrated significant hypoexpression in D and AD groups compared to the C group. Our findings in corpus cavernosum showed downregulated miRNA-155 and miRNA-199 levels associated with upregulated protein expression and unaltered mRNA expression of ET receptors suggesting decreased ET receptor turnover, which can contribute to erectile dysfunction in diabetic rats exposed to high alcohol levels.

Asunto(s)

RESUMEN

The Maryland aggregate pathology index (MAPI) score is an important tool developed to help pathologists in evaluating potential organs for transplantation. It is based on analysis of five variables (present or absent): arteriolar hyalinosis (4 points), periglomerular fibrosis (2 points), arterial wall-lumen ratio superior to 0.5 (2 points), global glomerulosclerosis in more than 15% of glomeruli (2 points), and interstitial scar (3 points). Kidneys with a MAPI score >7 points are considered inadequate for donation. This study aimed to evaluate pathology agreement between frozen sections (FS) and paraffin sections (PS) using the MAPI score in a cohort of 262 biopsy specimens obtained at the General Hospital of Fortaleza, Brazil. We performed a retrospective review of pathological reports of FS (signed out by an on-call pathologist) and their corresponding PS (authorized by a specialist in renal pathology). Agreement was calculated using the Kappa test. Kappa values ranging from 0.29 to 0.51 were obtained when MAPI parameters were separately evaluated. When the score was used, the coefficient was 0.59. Fourteen of 262 kidneys were classified as inadequate for donation using PS and 8 cases were diagnosed using FS. There were no differences between wedge-shaped and filiform samples, apart from the mean number of glomeruli. Discordant cases had no statistical difference from concordant ones when clinical and macroscopic pathological parameters were analyzed. The MAPI score can be useful to minimize disagreements between FS and PS, but more effort should be made to standardize criteria and enable pathologists to recognize chronic lesions in FS samples.

Asunto(s)

RESUMEN

Nitric oxide (NO) is identified as a signaling molecule involved in many cellular or physiological functions, including meiotic maturation of cattle oocytes. This study aimed to evaluate the effect of supplementation of culture medium with the L-arginine (L-arg, NO synthesis precursor) in nuclear maturation of oocytes, concentrations of nitrate/nitrite, progesterone (P4), and 17ß-estradiol (E2) in the culture medium; and the cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP) intracellular concentrations in the cumulus-oocyte complexes (COCs) during the first hours of maturation in the presence of hemisections (HSs) of the follicular wall (control -ve). The addition of 5.0-mM L-arg increased (P < 0.05) the percentage of oocytes at the germinal vesicle breakdown stage after 7 hours of cultivation compared with control -ve. All concentrations of L-arg (2.5, 5.0, and 10.0 mM) increased the percentage of oocytes that reached the metaphase I (MI) at 15 hours (P < 0.05) but do not affect the progression from MI to metaphase II (P > 0.05) at 22 hours. All concentrations of L-arg tested increased (P < 0.05) the percentage of cumulus cells with plasma membrane integrity at 22 hours of cultivation. L-arginine did not change (P > 0.05) the nitrate/nitrite, P4, and E2 concentrations in relation to control -ve at any of the times tested. In immature COCs, immediately after being removed from the follicles (0 hours), the intracellular concentration of cGMP in the control -ve and treatment with 5-mM L-arg progressively decreased (P < 0.05) after the first hour of cultivation; however, COCs treated with 5.0-mM L-arg had higher concentrations of cGMP at 1 hour of cultivation (P < 0.05). The cAMP concentration of COCs supplemented or not with 5.0-mM L-arg progressively increased until 3 hours of cultivation and at, 6 hours, decreased (P < 0.05). The results show, in using this system, that (1) the mechanisms that give the oocyte the ability to restart the meiosis until MI after adding 5.0-mM L-arg do not involve changes in the concentration of nitrate/nitrite, P4, and E2 in the culture medium and (2) L-arg acts on a pathway that involves changing the cGMP concentration but does not involve changing cAMP concentration. More studies are needed to assess whether the observed effects of L-arg during IVM using this system are via NO or not and what the role is in increasing the viability of cumulus cells in the resumption and progression of meiosis until MI.

Asunto(s)

RESUMEN

Skin aging is a complex process that may be caused by factors that are intrinsic and extrinsic to the body. Ultraviolet (UV) radiation represents one of the main sources of skin damage over the years and characterizes a process known as photoaging. Among the changes that affect cutaneous tissue with age, the loss of elastic properties caused by changes in elastin production, increased degradation and/or processing produces a substantial impact on tissue esthetics and health. The occurrence of solar elastosis is one of the main markers of cutaneous photoaging and is characterized by disorganized and non-functional deposition of elastic fibers. The occurrence of UV radiation-induced alternative splicing of the elastin gene, which leads to inadequate synthesis of the proteins required for the correct assembly of elastic fibers, is a potential explanation for this phenomenon. Innovative studies have been fundamental for the elucidation of rarely explored photoaging mechanisms and have enabled the identification of effective therapeutic alternatives such as cosmetic products. This review addresses cutaneous photoaging and the changes that affect elastin in this process.

Asunto(s)

RESUMEN

We conducted a mini-review of the literature, focusing on aging-related systemic inflammation and its association with vitamin D (VitD). As main findings, data indicate that inflammation in aging seems to have multiple origins, including immunosenescence, and from intestinal and adipose tissue, where VitD may modulate these three factors, through mechanisms not totally known. From the selected studies, three randomized clinical trials of VitD supplementation showed improvements in inflammatory status, whereas two studies did not. Ten epidemiological studies showed associations between VitD and inflammation, whereas two studies did not. One case study reinforced this association. As such, we can assume a reasonable association between VitD and inflammation in the elderly, and a promising role of supplementation in some situations. However, most studies did not take into account environmental and individual factors such as the season of the year, latitude, skin color or even the use of some medicines; in addition, the doses, time of intervention and the sample sizes differed between the studies. In conclusion, although more controlled VitD studies, both clinical and epidemiological, are necessary, it is important to remember the network of factors involved in systemic inflammation in the elderly; an understanding of the dietetic and non-dietetic factors is needed to offer a realistic approach.

Asunto(s)

RESUMEN

The rat is probably the most commonly used animal in scientific research. There are many benefits to its use such as: ability to work a large number of animals allowing greater statistical validity, the relatively short life cycles. However, the scant literature regarding the anatomy and morphology of these animals is also old and not very descriptive. The objective of this research is to study the macroscopic morphometric aspects of several parameters that have not been described yet regarding the heart of Wistar rats in different phases of their lives. Thirty-six adult male and female rats (Rattus norvegicus) weighting 150-770 g were randomly divided into 6 experimental groups. The heart was then carefully dissected and removed from the chest. After this process, the heart had their weight measured on a precision scale HELMAC HM100, and for each front section of the heart related measures were taken through a semi-automatic image analysis of Kontron Build Analyse (Minimop). The percentage ratio between the relative heart weight to body weight was between 0.5 and 0.7% in the animals with body weight up to 650 g. The maximum and minimum diameters were always statistically lower in females compared to males. The measurements showed the hearts of the females shorter, narrower, smaller and lighter than those of males. Over the life of these females, although the heart weight increases, the heart apparently keeps its shape and size. Furthermore, the hearts of males narrow and stretch along their development.

La rata es probablemente el animal más utilizado en investigaciones científicas. Hay muchos beneficios por su uso como la capacidad de trabajar con un gran número de animales permitiendo una mayor validez del punto de vista estadístico o el ciclo de vida relativamente corto del animal. Sin embargo, la escasa literatura sobre la anatomía y la morfología de la rata es antigua y no muy descriptiva. El objetivo de esta investigación fue estudiar parámetros morfométricos macroscópico no descritos con respecto al corazón de la rata Wistar en diferentes fases de la vida. Treinta y seis ratas (Rattus norvegicus) adultas, hembras y machos pesando entre 150­770 g, fueron divididas al azar en 6 grupos diferentes. El corazón fue cuidadosamente disecado y retirado del tórax. Cada corazón fue pesado en una balanza de precisión y para cada sección frontal del corazón fueron tomadas medidas relativas mediante un análisis de imágen semi-automático Kontron Build Analyse (Minimop). El porcentaje de proporción entre el peso relativo del corazón y el peso del cuerpo fue entre 0,5­0,7% en animales con peso corporal de hasta 650 g. Los diámetros máximos y mínimos fueron estadísticamente menores en hembras comparádolos con machos. Las medidas mostraron que los corazones en las hembras son más cortos, angostos, pequeños y livianos que en machos. Durante la vida de estas hembras, aunque el peso del corazón aumenta, aparentemente mantiene su forma y su tamaño. Por otro lado, los corazones de los machos se estiran y se estrechan durante su desarrollo.

Asunto(s)

RESUMEN

The metric signature topological transitions associated with the propagation of electromagnetic waves in a dispersive metamaterial with frequency-dependent and anisotropic dielectric and magnetic responses are examined in the present work. The components of the reciprocal-space metric tensor depend upon both the electric permittivity and magnetic permeability of the metamaterial, which are taken as Drude-like dispersive models. A thorough study of the frequency dependence of the metric tensor is presented which leads to the possibility of topological transitions of the isofrequency surface determining the wave dynamics inside the medium, to a diverging photonic density of states at some range of frequencies, and to the existence of large wave vectors' modes propagating through the metamaterial.

RESUMEN

BACKGROUND: The highest prevalence of protein-energy undernutrition is observed during early childhood, being also a time in which the presence of dental caries can be unusually aggressive. The present study aimed to verify if different levels of undernutrition could influence the risk of early childhood caries (ECC), in the presence of other predisposing factors. METHODS: One hundred and twenty undernourished 12-70 month old children, with or without ECC, were selected. Undernourished children were classified as being mildly, moderately or severely undernourished. All children were examined for determination of decayed, missing and filled surfaces (dmfs). Total protein concentration in saliva was analysed by the Bradford method. For microbiological analysis, mitis salivarius-bacitracin agar medium was used. A binary logistic regression model was applied to test the simultaneous influence of different variables over caries experience. RESULTS: The risk of ECC was significantly higher with an increase in age (p = 0.000) and mutans streptococci counts (p = 0.032). Comparisons with the normal-weight group showed that mildly (p = 0.004) and severely undernourished children (p = 0.037) had a higher risk of experiencing ECC, but this risk was not significantly elevated among moderately undernourished children (p = 0.158). CONCLUSIONS: Our results suggest that mildly and severely undernourished children have an increased risk of experiencing dental caries. Age is highly associated with the disease in this population.

Asunto(s)

RESUMEN

OBJECTIVE: Stem cells have the ability to renew themselves and differentiate into various cell types. For this reason, numerous research groups have been studying these cells for their therapeutic potential. Some of the therapies, however, are not producing the expected results because of contamination by other cell types, especially by fibroblasts. In the cosmetic industry, stem cells are used to test the efficacy of anti-ageing and rejuvenation products. The purpose of this work was to gain a better understanding of the differences in phenotype, in gene expression associated with stem cells, in the pattern of cell surface proteins and in the differentiation capacity of adipose-derived stem cells, of skin-derived stem cells and of commercially available fibroblasts. METHODS: In this study, we compared fibroblasts with mesenchymal stem cells derived from bone marrow, skin (dermis) and adipose tissue, to assess the differentiation potential of fibroblasts. Dermal and adipose stem cells were isolated from aesthetic surgery patients, and fibroblasts were obtained from a commercial source. The following parameters were used in this study: immunophenotypic profile (positive: CD29, CD73, CD90 and CD105; negative: CD14, CD45 and HLA-DR); differentiation into osteoblastic, chondrogenic and adipogenic cell types; and PCR array to analyse the gene expression of cells isolated from different culture passages. RESULTS: Fibroblasts express the same cell immunophenotypic markers, as well as the genes that are known to be expressed in stem cells, and were shown to be expressed also in adipose and dermis stem cells. Fibroblasts are also able to differentiate into the three cell lineages mentioned above, that is, adipocytes, osteocytes and chondrocytes. CONCLUSION: Human dermal fibroblasts have a potential to adhere to plastic surfaces and differentiate into other cell types. However, for stem cells intended to be used in cosmetics, experiments conducted with contaminated fibroblasts may produce poor or even falsely negative results for the efficacy of the active ingredient or formulation and thus conceal their promising effects as anti-ageing and skin rejuvenation products.

Asunto(s)

RESUMEN

We examined the expression of anti-apoptotic genes (XIAP and Bcl-2) and apoptotic genes (cytochrome c, caspase-9, Apaf-1) in tissue samples of patients with superficial bladder cancer. Thirty-two bladder cancer tissue samples (8 papillary urothelial neoplasm of low malignant potential, 10 low-grade, and 14 high-grade) and 8 normal bladder tissue samples from necropsy were used for the study of gene expression by real-time PCR analysis. Analysis of the expression of apoptotic gene constituents of an apoptosome demonstrated an increase in Apaf-1 expression in the three tumor grades when compared with the control (P < 0.01, P < 0.05, and P < 0.01), low expression of caspase-9 in all groups (P < 0.05), and an increase in cytochrome c expression in all tumor grades in relation to the control, although without statistically significant difference. The expression of anti-apoptotic genes revealed an increase in XIAP expression in all tumor grades in relation to the control, although without statistically significant difference, and low expression of Bcl-2 in all tumor grades and the control (P < 0.05). The results proved that there is low evidence of apoptotic activity by the intrinsic pathway, demonstrated by the low expression of caspase-9 and considerable increase in XIAP expression, which may render these genes potential therapeutic targets in bladder cancer treatment.

Asunto(s)

RESUMEN

INTRODUCTION: We report a case of an emergency high-risk patient with a pararenal aortic aneurysm. REPORT: Our patient had a pararenal aneurysm with two components: a wide-neck saccular aneurysm below the left renal artery and a fusiform aneurysm. A self-expandable aortic stent was deployed covering both renal arteries, the saccular aneurysm was embolised with microcoils and a bifurcated aortic endograft was anchored inside the aortic stent. The aortic stent imprisoned the microcoils and avoided proximal type I endoleak. The tomography done 15 months after the procedure showed no endoleaks. DISCUSSION: A self-expandable aortic stent can provide an alternative for emergency high-risk patients with pararenal aortic aneurysms.

Asunto(s)

RESUMEN

A proteína Mx1 é codificada por um gene induzido por interferon e compartilha a organização de seus domínios, a capacidade de homo-oligomerização e associação com membranas com as grandes dinaminas GTPases. A proteína Mx1 está envolvida na resposta contra um grande número de vírus de RNA, como aqueles pertencentes à família Buniavírus e o vírus influenza. Curiosamente, o gene MX1 foi encontrado como silenciado por metilação em diversos processos neoplásicos, incluindo carcinomas de cabeça e pescoço de células escamosas. Neste cenário, o silenciamento gênico de MX1 está associado à imortalização de uma série de linhagens celulares neoplásicas. Assim, Mx1 se destaca como uma das principais proteínas envolvidas nas respostas imunes induzidas por interferon e também desempenha um importante papel no controle do ciclo celular. Aqui discutimos os aspectos funcionais da proteína Mx1 abordando sua atividade antiviral, organização estrutural, envolvimento com neoplasias e, principalmente, os aspectos funcionais obtidos pela determinação de seus parceiros celulares.

The Mx1 protein is encoded by an interferon-induced gene and shares domain organization, homo-oligomerization capacity and membrane association with the large dynamin-like GTPases. The Mx1 protein is involved in the response to a large number of RNA viruses, such as the bunyavirus family and the influenza virus. Interestingly, it has also been found as a methylation-silenced gene in several types of neoplasm, including head and neck squamous cell carcinoma. In this scenario, MX1 gene silencing is associated with immortalization in several neoplastic cell lines. Thus, Mx1 stands out as one of the key proteins involved in interferon-induced immune response and also plays an important role in cell cycle control. Here we discuss some of the functions of the Mx1 protein, including its antiviral activity, protein folding and involvement in neoplasia, as well as those revealed by investigating its cellular partners.

Asunto(s)

RESUMEN

Avaliaram-se o papel do óxido nítrico (NO) por meio da inibição da enzima óxido nítrico sintase induzível (iNOS), após a adição da aminoguanidina (AG), na motilidade, no vigor e na integridade da membrana plasmática nos tempos de 15, 60, 120, 180, 240 e 300min e a atividade mitocondrial e a capacitação de espermatozoides bovinos após 300min de cultivo. Adicionaram-se diferentes concentrações (0,001, 0,01 e 0,1M) de AG durante a capacitação induzida pela heparina e 500μM de nitroprussiato de sódio (SNP, doador de NO) à concentração deletéria. A adição de 0,1M de AG diminuiu a motilidade e o vigor espermático e a integridade da membrana (P<0,05). A adição de SNP ao meio de cultivo com 0,1M de AG somente reverteu a integridade da membrana após 300min. A inibição da síntese de NO pela adição de AG não alterou a atividade mitocondrial. A percentagem de oócitos penetrados com espermatozoides tratados com 0,01 e 0,1M de AG diminuiu 20,3 e 100 por cento, respectivamente, em relação aos não tratados (controle) (P<0,05), contudo houve aumento de 15 por cento na percentagem de oócitos desnudados penetrados com espermatozoides capacitados em presença de 0,1M de AG. Conclui-se que a inibição da síntese de NO pela AG diminuiu a qualidade espermática durante a capacitação de espermatozoides bovinos in vitro, exceto a atividade mitocondrial. Somente a integridade da membrana foi revertida após adição de NO, sugerindo diferentes vias de ação do NO na qualidade espermática ao longo da capacitação in vitro de espermatozoides bovinos.

The role of nitric oxide (NO) was evaluated by inhibition of inducible nitric oxide synthase (iNOS), with aminoguanidine (AG) on motility, vigor, and plasmatic membrane integrity of bovine spermatozoa culture after 15, 60, 120, 180, 240, and 300min and on mitochondrial activity and capacitation after 300min, respectively. Different concentrations, 0.001, 0.01, and 0.1M of AG were added during the heparin induced capacitation and sodium nitroprusside (SNP, NO donor-500μM) to the deleterious concentration. The addition of 0.1M of AG diminished progressive motility, spermatic vigor, and membrane integrity (P<0.05). SNP addition to the 0.1M of AG did revert only plasmatic membrane integrity after 300min. Mitochondrial activity was not influenced by addition of AG. Percentage of penetrated oocytes after addition of 0.01 and 0.1M of AG diminished, 20.3 and 100 percent, respectively, in relation to the control oocytes (P<0.05). However, an increase of 15 percent was observed when denuded oocytes were used with 0.1M AG treated sperm (P<0.05). It was concluded that the inhibition of NO synthesis with aminoguanidine diminished sperm quality during in vitro capacitation of bovine spermatozoa, except the mitochondrial activity. Only membrane integrity was reverted with the addition of NO to culture medium, suggesting different pathways of NO action on bovine sperm quality during in vitro capacitation.

Asunto(s)

RESUMEN

Avaliaram-se o papel do óxido nítrico (NO) por meio da inibição da enzima óxido nítrico sintase induzível (iNOS), após a adição da aminoguanidina (AG), na motilidade, no vigor e na integridade da membrana plasmática nos tempos de 15, 60, 120, 180, 240 e 300min e a atividade mitocondrial e a capacitação de espermatozoides bovinos após 300min de cultivo. Adicionaram-se diferentes concentrações (0,001, 0,01 e 0,1M) de AG durante a capacitação induzida pela heparina e 500μM de nitroprussiato de sódio (SNP, doador de NO) à concentração deletéria. A adição de 0,1M de AG diminuiu a motilidade e o vigor espermático e a integridade da membrana (P<0,05). A adição de SNP ao meio de cultivo com 0,1M de AG somente reverteu a integridade da membrana após 300min. A inibição da síntese de NO pela adição de AG não alterou a atividade mitocondrial. A percentagem de oócitos penetrados com espermatozoides tratados com 0,01 e 0,1M de AG diminuiu 20,3 e 100 por cento, respectivamente, em relação aos não tratados (controle) (P<0,05), contudo houve aumento de 15 por cento na percentagem de oócitos desnudados penetrados com espermatozoides capacitados em presença de 0,1M de AG. Conclui-se que a inibição da síntese de NO pela AG diminuiu a qualidade espermática durante a capacitação de espermatozoides bovinos in vitro, exceto a atividade mitocondrial. Somente a integridade da membrana foi revertida após adição de NO, sugerindo diferentes vias de ação do NO na qualidade espermática ao longo da capacitação in vitro de espermatozoides bovinos.(AU)

The role of nitric oxide (NO) was evaluated by inhibition of inducible nitric oxide synthase (iNOS), with aminoguanidine (AG) on motility, vigor, and plasmatic membrane integrity of bovine spermatozoa culture after 15, 60, 120, 180, 240, and 300min and on mitochondrial activity and capacitation after 300min, respectively. Different concentrations, 0.001, 0.01, and 0.1M of AG were added during the heparin induced capacitation and sodium nitroprusside (SNP, NO donor-500μM) to the deleterious concentration. The addition of 0.1M of AG diminished progressive motility, spermatic vigor, and membrane integrity (P<0.05). SNP addition to the 0.1M of AG did revert only plasmatic membrane integrity after 300min. Mitochondrial activity was not influenced by addition of AG. Percentage of penetrated oocytes after addition of 0.01 and 0.1M of AG diminished, 20.3 and 100 percent, respectively, in relation to the control oocytes (P<0.05). However, an increase of 15 percent was observed when denuded oocytes were used with 0.1M AG treated sperm (P<0.05). It was concluded that the inhibition of NO synthesis with aminoguanidine diminished sperm quality during in vitro capacitation of bovine spermatozoa, except the mitochondrial activity. Only membrane integrity was reverted with the addition of NO to culture medium, suggesting different pathways of NO action on bovine sperm quality during in vitro capacitation.(AU)

Asunto(s)