• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 7
  • 2
  • 1
  • 1
  • Tagged with
  • 12
  • 12
  • 6
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Analyses of spermatozoa surface proteins using different separation techniques

Fortuin, Kay Arlene January 2013 (has links)
Magister Scientiae (Medical Bioscience) - MSc(MBS) / Passage of spermatozoa through the female reproductive tract is essential for the regulation of fertilization, ensuring that healthy sperm reach the oocyte. Previous studies were devoted to morphological selection of sperm cells by the cervical mucus. However, research prove that the loss of integrity of the sperm plasma membrane is associated with infertile men, irrespective of their normal semen parameters. This indicates that the sperm plasma membrane plays an important role in fertilization. Further studies indicated that sperm surface proteins assist penetration through the female reproductive tract and would therefore provide useful insight in understanding other factors associated with male infertility. The aim of this project was to determine if there are any differences between sperm surface proteins of fertile donor samples in relation to infertile patient samples using different separation techniques and different detergents. Three different sperm separation techniques were employed, including wash, swim-up (SU) and Percoll density gradient centrifugation (DGC).Parallel to this, the deoxy-ribose nucleic acid (DNA) fragmentation of these cells were analysed for comparison of the extent of DNA damage induced due to different separation techniques used. This provided evidence that the best separation technique is the DGC as it minimises the amount of DNA fragmentation caused. Four different detergents were used in the process of extracting the membrane proteins from spermatozoa, namely sodium dodecyl sulphate (SDS), saponin,cetyl-trimethyl-ammonium bromide (CTAB), and TWEEN-20. The membrane proteins were then separated on a12% SDS poly-acrylamide gel electrophoresis (PAGE), and analysed by Coomassie blue and silver staining techniques as well as densitometry. Due to the different chemical nature of the detergents that extracted different surface proteins, CTAB (cationic) and SDS (anionic) extracted the most because of its strong solubilising abilities as non-ionic detergents. Common proteins that were extracted in donor samples included; 115, 92.5, 89, 61, 55.5, 51.5, 47, 44.5, 43, 38.5, 34 and 28 kDa proteins. In patients, commonly occurring proteins included; 92.5, 74.5, 70, 60.5, 51.5, 50, 44.5, 43, 36, 29.5, and 25.5 kDa proteins. Marked differences were found between membrane proteins extracted from donor samples in comparison to patient samples. Identification of these proteins was done using the SwissProt database and a literature search. Mostly non-genomic progesterone receptors were identified; others included oestrogen receptor, a phosphotyrosyl protein, P34H, equatorial segment protein, mannose lectin receptor, human guanylylcyclase receptor, epididymal protease inhibitor receptor, PH30 and estradiol binding protein. The function of the membrane surface proteins identified in this study plays a vital role in fertilization. A few of these functions include sperm attachment and binding to the oocyte as well as penetration thereof. Others play a role in signalling events such as capacitation, hyperactivation and acrosome reaction. The absence of these proteins in patient sperm possibly accounts for the functional inability to successfully achieve fertilization suggesting that this provides molecular insight to reasons for infertility amongst men. In addition to this, proteins presented by patient samples that were absent in healthy donors may too account for their infertility status. Estradiol binding protein and PH30 are two proteins presented only in patient samples. Their function plays a role in the inhibition of the acrosome reaction and sperm-egg fusion, respectively. In conclusion, these differences in protein expression between fertile donors and patients may form the molecular basis of infertility amongst men and indicates possibilities for novel proteonomic approaches to improve andrological diagnosis in future.
2

Platelet-Activating Factor Treatment of Human Spermatozoa Enhances Fertilization Potential

Minhas, Brijinder S. 01 January 1993 (has links)
No description available.
3

Correlation between Fertilization, Cleavage and Pregnancy Rate with Sperm DNA-Fragmentation Index (DFI)

Nymo, Kaitlin January 2008 (has links)
<p>The chromatin integrity in sperm cells is vital for successful pregnancy. In this</p><p>study DNA-damage was evaluated in sperm cells from 50 men attending In Vitro Fertilization</p><p>(IVF) or Intra Cytoplasmic Sperm Injection (ICSI) treatment. Male semen samples were</p><p>purified with a two-shift gradient before the sperm cells were treated with the Halosperm® Test</p><p>Kit and evaluated for DNA-damage. The samples were divided in two groups according to DNAFragmentation</p><p>Index (DFI) of 30 % and the results correlated with fertilization, cleavage and</p><p>pregnancy rate. Men with DFI ≥ 30 % had a higher fertilization and pregnancy rate and a lower</p><p>cleavage rate compared to men with DFI ≤ 30 %. The conclusions were that fertilization in vitro</p><p>may be independent of the degree of DNA-damage, the embryonic development could be</p><p>seriously disrupted by damaged sperm cells, and the pregnancy rate showed no correlation to a</p><p>DFI threshold of 30 %.</p>
4

Correlation between Fertilization, Cleavage and Pregnancy Rate with Sperm DNA-Fragmentation Index (DFI)

Nymo, Kaitlin January 2008 (has links)
The chromatin integrity in sperm cells is vital for successful pregnancy. In this study DNA-damage was evaluated in sperm cells from 50 men attending In Vitro Fertilization (IVF) or Intra Cytoplasmic Sperm Injection (ICSI) treatment. Male semen samples were purified with a two-shift gradient before the sperm cells were treated with the Halosperm® Test Kit and evaluated for DNA-damage. The samples were divided in two groups according to DNAFragmentation Index (DFI) of 30 % and the results correlated with fertilization, cleavage and pregnancy rate. Men with DFI ≥ 30 % had a higher fertilization and pregnancy rate and a lower cleavage rate compared to men with DFI ≤ 30 %. The conclusions were that fertilization in vitro may be independent of the degree of DNA-damage, the embryonic development could be seriously disrupted by damaged sperm cells, and the pregnancy rate showed no correlation to a DFI threshold of 30 %.
5

Comparison between two different freezing solutions toevaluate the sperm survival after vapor freezing andsperm preparation.

Ordonez, Daniela January 2016 (has links)
Cryopreservation is used to freeze and store donor’s sperm, from men who are going throughcertain medical treatments such as chemotherapy or radiotherapy and from men withazoopermia or severe oligozoospermia. Stored sperm samples are used in artificialreproductive technologies. Formation of ice crystals is the biggest problem when freezingcells because of the risk severe damage to the cells. To guarantee optimal survival rates infrozen sperm samples, cryoprotectants which protect sperms from ice crystals formations, isadded.The main objective of the study was to compare two different freeze solutions and theirimpact on sperm survival in frozen sperm samples. In addition, an additional aim was todetermine if the amount of motile sperm changes when the samples is left for two hours inroom temperature.In this study, 31 samples were used. Each sample was divided into two groups. The firstgroup was mixed with a SpermFreeze Solution™ and the second group was mixed withSperm CryoProtectTM II. All samples were frozen using cooling vapor and stored in tankswith liquid nitrogen. The concentration of motile sperm was measured after thawing andpreparation. SpermFreeze SolutionTM showed significant better results in the number ofsperm who survived after freezing and thawing process Also, the results showed that werewas no significant difference on concentration of motile sperm in samples after being left atroom temperature for two hours. In summary, an improvement in the process of preparationrecommends to be performed to reduce the mechanical stress to ensure a greater quantity ofmotile sperm after the whole process.
6

Parallel evaluation of Doxorubicin inducing Genetic damage in human lymphocytes and sperm using the Comet assay and spectral karyotyping

Anderson, Diana, Baumgartner, Adolf, Cemeli, Eduardo, Schmid, Thomas E. January 2004 (has links)
No / In recent years, two techniques for detecting genetic damage in the whole genome have gained importance: the alkaline comet assay, to detect DNA damage such as strand breaks and alkali-labile sites, and a multicolour FISH method, spectral karyotyping (SKY), to identify chromosomal aberrations simultaneously in all metaphase chromosomes. In the present study, the induction of DNA damage in human sperm and lymphocytes in vitro has been studied employing an anticancer drug, doxorubicin (DX). An increase in DNA damage was observed with the comet assay as the median per cent head DNA of sperm significantly decreased from 82.07 and 85.14% in the untreated control groups to 63.48 and 72.52% at doses of 0.8 µM DX. At 1.6 µM the percentage declined to 60.96% (the corresponding tail moment increased from 4.42 to 12.19). In stimulated lymphocytes, a significant increase was observed in tail moment, from 0.72 and 0.53 in controls to 15.17 and 12.10 at 0.2 µM DX, continuing at the same level to a final concentration of 1.6 µM. Structural aberrations found in the parallel SKY study in stimulated lymphocytes at 0.2 µM DX consisted of 14% chromatid-type and 2% chromosome-type aberrations; none were found in controls. The SKY results correlate very well with the findings of the comet assay in lymphocytes where DNA damage was observed at similar doses. This study is the first reporting use of the comet assay and SKY analysis in parallel after chemical treatment. The potential of the two techniques together is evident, as they represent a set of assays feasible for evaluating damage in human somatic and germ cells after chemical treatment (i) by direct observation of two different end-points, detecting general DNA damage and chromosomal aberrations and (ii) by extrapolation from lymphocytes to sperm, which provides a `parallelogram¿ approach in human cells.
7

Effects of the antimalarial compound cryptolepine and its analogues in human lymphocytes and sperm in the Comet assay

Gopalan, Rajendran C., Emerce, E., Wright, Colin W., Karahalil, B., Karakaya, A.E., Anderson, Diana January 2011 (has links)
no / Malaria is a mosquito-borne infectious disease caused by the genus Plasmodium. It causes one million deaths per year in African children under the age of 5 years. There is an increasing development of resistance of malarial parasites to chloroquine and other currently used anti-malarial drugs. Some plant products such as the indoloquinoline alkaloid cryptolepine have been shown to have potent activity against P. falciparum in vitro. On account of its toxicity, cryptolepine is not suitable for use as an antimalarial drug but a number of analogues of cryptolepine have been synthesised in an attempt to find compounds that have reduced cytotoxicity and these have been investigated in the present study in human sperm and lymphocytes using the Comet assay. The results suggest that cryptolepine and the analogues cause DNA damage in lymphocytes, but appear to have no effect on human sperm at the assessed doses. In the context of antimalarial drug development, the data suggest that all cryptolepine compounds and in particular 2,7-dibromocryptolepine cause DNA damage and therefore may not be suitable for pre clinical development as antimalarial agents.
8

Gender selection: separation techniques for X- and Y-chromosome bearing human spermatozoa

Van Der Linde, Michelle 12 1900 (has links)
Thesis (MScMedSc)-- Stellenbosch University, 2013. / ENGLISH ABSTRACT: Preconceptual sex selection is an ethically justifiable process whereby X- and Y-chromosome bearing spermatozoa are isolated prior to fertilization of the oocyte in order to generate either a male or a female offspring. Although various separation techniques are available, none can guarantee 100% accuracy. There are various physiological differences between X- and Y-chromosome bearing spermatozoa which can be used to separate these two populations of sperm. For the purpose of this study, X- and Y-chromosome bearing spermatozoa were separated based on (1) their respective abilities to remain viable when subjected to adverse environments, including extreme pH values, increased temperatures and various hydrogen peroxide (H2O2) concentrations; (2) the ability of Y-chromosome bearing spermatozoa to swim faster and/or more progressively than X-chromosome bearing spermatozoa; and (3) the X-chromosome bearing spermatozoa’s increased size and weight when compared to the Y-chromosome bearing spermatozoa. The efficacy of live and dead cell separation through (i) Magnetic Antibody Cell Separation (MACS) and (ii) a modified swim-up technique was also assessed and compared. Changes in the sex-chromosome ratio of samples were established by double-label fluorescent in situ hybridization (FISH) before and after processing. Sperm motility (CASA) and viability (eosin/nigrosin) was assessed before and after each intervention. Ethical clearance for this study was granted by the Health Research Ethics Committee 1 (Ethics #: S13/04/068). The results indicated successful enrichment of X-chromosome bearing spermatozoa upon incubation in acidic media, increased temperatures, and H2O2. In contrast, Y-chromosome bearing spermatozoa were successfully enriched through a direct swim-up method as well as discontinuous gradient centrifugation. In conclusion, this study demonstrated the potential role for physiological differences between X- and Y-chromosome bearing spermatozoa in the development of preconceptual gender selection through sperm sorting. / AFRIKAANSE OPSOMMING: Prekonsepsie geslagselektering is 'n eties regverdigbare proses waardeur X- en Y- chromosoom draende spermatosoë geïsoleer word voordat bevrugting van die oösiet plaasvind, om óf 'n manlike óf 'n vroulike nageslag te genereer. Alhoewel verskeie skeidingstegnieke beskikbaar is, kan geeneen 100% akkuraatheid waarborg nie. Daar bestaan verskeie fisiologiese verskille tussen X- en Y- chromosoom draende spermatosoë wat skeiding van hierdie twee groepe spermatosoë moontlik kan maak. Vir die doel van hierdie studie is skeidingsmetodes vir die X- en Y- chromosoom draede spermatosoë gebaseer op (1) hul onderskeie vermoëns om lewensvatbaar te bly tydens blootstelling aan ‘n ongunstige milieu, insluitend ekstreme pH waardes, verhoogde temperature en verskeie waterstofperoksied (H2O2) konsentrasies; (2) die vermoë van die Y-chromosoom draende spermatosoon om vinniger en/of meer progressief as X-chromosoom draende spermatosoë te swem; en (3 ) die X-chromosoom draende spermatosoon se verhoogde grootte en gewig in vergelyking met die Y- chromosoom draende spermatosoon. Die effektiwiteit van die (i) Magnetiese Anti-liggaam Sel Skeidingstegniek (MACS) en (ii) 'n aangepaste weergawe van die op-swem tegniek om lewendige en dooie selle te skei is ook bepaal en vergelyk. Veranderinge in die geslagschromosoom verhouding van die monsters is bepaal deur dubbel-etiket fluoresensie in situ hibridisering (FISH) voor en na verwerking. Spermmotiliteit (CASA) en lewensvatbaarheid (eosien/nigrosin) is bepaal voor en na elke intervensie. Etiese goedkeuring vir hierdie studie is verleen deur die Gesondheids-Navorsingsetiekkomitee 1 (Etiese # : S13/04/068). Die resultate dui suksesvolle verryking van X-chromosoom draende spermatosoë deur inkubasie in suur media, verhoogde temperature, en H2O2. Y-chromosoom draende spermatosoë is verryk deur middel van 'n direkte op-swem metode sowel as diskontinue gradiënt sentrifugering . Ten slotte, hierdie studie toon die potensiële rol vir fisiologiese verskille tussen X- en Y- chromosoom draende spermatosoë in die ontwikkeling van prekonsepsie geslagselektering metodes deur skeiding van X- en Y-chromosoom draende sperme.
9

Estudo in vitro da interação entre herbicidas e espermatozoide humano utilizando a Espectroscopia de Espalhamento Raman / In vitro Interaction study between herbicides and human sperm using Raman Scaterring Spectroscopy

Oliveira, Tamiris Garbiatti de 23 March 2015 (has links)
Made available in DSpace on 2016-01-26T18:56:04Z (GMT). No. of bitstreams: 1 Tamiris Garbiatti de Oliveira.pdf: 1606086 bytes, checksum: cf9e26811174e34243865dc9dfffec23 (MD5) Previous issue date: 2015-03-23 / The unlimited use of pesticides, besides contribute with to increase environmental pollution, is also influencing negatively the health of the living beings, including the people health. Many studies show the result these chemicals in the reproductive system of animals and even same at man, can cause infertility problem, which can originate, among other factors, the low sperm quality and quantity. This is study aimed at evaluating human sperm quality parameters and the chemical evaluation of the core of the sperm trough Raman Scaterring Spectroscopy, after in vitro exposure to different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) and atrazine. The choice of the use of the these herbicides was because they are widely use throughout the world, especially in Brazil, highlighted the west Paulista region, used at cane sugar plantation, significant culture of the region. In this context, sperm samples were selected according to the normal testing parameters that evaluate sperm quality, such as liquefaction, viscosity, appearance, volume, pH, sperm, vitality, morphology and motility. Semen samples of 10 healthy donor were exposed to study herbicides varying the concentration and time. After the different exposures (0.05, 0.5, 1.0, 5.0 and 125 &#956;g/mL, 30 and 60 min), the analysis of motility and vitality were again evaluated. The Raman Scaterring spectra were obtained from samples control sperm and after exposure to the herbicide 2,4-D e atrazine at concentration of 125 &#956;g/mL and 60 min incubation. The progressive motility and total motility decreased from the concentration 0,5 &#956;g/mL at times 30 and 60 minutes while the percentage of sperm properties increased. The progressive motility and total motility decreased from the concentration 0.5 mg / mL at times 30 and 60 minutes while the percentage of sperm immotile increased. The vitality (viable sperm) decreased significantly (p <0.05) from the exposure concentration 0.5 &#956;g/mL to 2,4-D and from 1.0 &#956;g/mL atrazine, at times 30 and 60 minutes, showing that there is a functional change of trend of human sperm after exposure to these herbicides, and this change is intensified with the exposure time factor and concentration of herbicides. Through the Raman Scaterring technique allowed us to characterize normal human sperm and exposed to herbicides and verify the change in the molecular structure in the exposed sperm, evidenced by changes in relative intensities of the bands 785, 1095, 1255, 1336, 1374, 1486 and 1575 cm-1 treated with 2,4-D and a decrease at 1095 after exposure to atrazine. These results indicate the modification of nitrogenous bases and the phosphate group that make up DNA present in the nucleus of the sperm. / A utilização desenfreada de praguicidas, além de contribuir com o agravamento da poluição ambiental, também está influenciando de forma negativa a saúde dos seres vivos, inclusive a saúde das pessoas. Muitos estudos mostram a interferência desses produtos químicos no sistema reprodutor de animais e até mesmo do homem, podendo acarretar problemas de infertilidade, que podem ser originados, dentre vários fatores, pela baixa quantidade e qualidade espermática. Este estudo visa á avaliação de parâmetros de qualidade espermática humana e a avaliação química do núcleo do espermatozoide, por meio de Espectroscopia de Espalhamento Raman, após a exposição in vitro a diferentes concentrações de ácido 2,4-diclorofenoxiacético (2,4-D) e atrazina. Estes herbicidas são amplamente utilizados em todo o mundo, principalmente no Brasil, em destaque a região do Oeste Paulista, por serem empregados na cana-de-açúcar, cultura significativa da região. Neste contexto, foram selecionadas amostras de espermatozoides de acordo com os parâmetros normais de testes que avaliam a qualidade espermática, como: liquefação, viscosidade, aparência, volume, pH, concentração de espermatozoides, vitalidade, morfologia e motilidade. Amostras de sêmen de 10 doadores saudáveis foram expostas aos herbicidas de estudo, variando o tempo e a concentração. Após as diferentes exposições (0,05; 0,5; 1,0; 5,0 e 125 &#956;g/mL, 30 e 60 min), as análises de motilidade e vitalidade foram novamente avaliadas. Os espectros de Espalhamento Raman foram obtidos das amostras de espermatozoide controle e após a exposição aos herbicidas 2,4-D e atrazina na concentração de 125 µg/mL em 60 min de incubação. A motilidade progressiva e motilidade total diminuíram a partir da concentração 0,5 &#956;g/mL nos tempos 30 e 60 min enquanto que a porcentagem de espermatozoides imóveis aumentou. A vitalidade (espermatozoides viáveis) diminuiu significativamente (p<0,05) a partir da exposição da concentração 0,5 &#956;g/mL para o 2,4-D e a partir de 1,0 &#956;g/mL para a atrazina, nos tempos 30 e 60min, mostrando-se que há uma tendência de alteração funcional do espermatozoide humano após a exposição a estes herbicidas, e esta alteração é intensificada com o fator de tempo de exposição e concentração dos herbicidas testados. Por meio da técnica de Espalhamento Raman foi possível caracterizar o espermatozoide humano normal e os expostos aos herbicidas e verificar a alteração na estrutura molecular nos espermatozoides expostos, evidenciadas pelas alterações nas intensidades relativas das bandas 785, 1095, 1255, 1336, 1374, 1486 e 1575 cm-1 do tratado com 2,4-D, e uma diminuição na banda de 1095 após a exposição à atrazina. Estes resultados indicam a alteração das bases nitrogenadas e do grupo fosfato que compõem o DNA presente no núcleo do espermatozoide.
10

Estudo in vitro da interação entre herbicidas e espermatozoide humano utilizando a Espectroscopia de Espalhamento Raman / In vitro Interaction study between herbicides and human sperm using Raman Scaterring Spectroscopy

Oliveira, Tamiris Garbiatti de 23 March 2015 (has links)
Made available in DSpace on 2016-07-18T17:46:21Z (GMT). No. of bitstreams: 1 Tamiris Garbiatti de Oliveira.pdf: 1606086 bytes, checksum: cf9e26811174e34243865dc9dfffec23 (MD5) Previous issue date: 2015-03-23 / The unlimited use of pesticides, besides contribute with to increase environmental pollution, is also influencing negatively the health of the living beings, including the people health. Many studies show the result these chemicals in the reproductive system of animals and even same at man, can cause infertility problem, which can originate, among other factors, the low sperm quality and quantity. This is study aimed at evaluating human sperm quality parameters and the chemical evaluation of the core of the sperm trough Raman Scaterring Spectroscopy, after in vitro exposure to different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) and atrazine. The choice of the use of the these herbicides was because they are widely use throughout the world, especially in Brazil, highlighted the west Paulista region, used at cane sugar plantation, significant culture of the region. In this context, sperm samples were selected according to the normal testing parameters that evaluate sperm quality, such as liquefaction, viscosity, appearance, volume, pH, sperm, vitality, morphology and motility. Semen samples of 10 healthy donor were exposed to study herbicides varying the concentration and time. After the different exposures (0.05, 0.5, 1.0, 5.0 and 125 &#956;g/mL, 30 and 60 min), the analysis of motility and vitality were again evaluated. The Raman Scaterring spectra were obtained from samples control sperm and after exposure to the herbicide 2,4-D e atrazine at concentration of 125 &#956;g/mL and 60 min incubation. The progressive motility and total motility decreased from the concentration 0,5 &#956;g/mL at times 30 and 60 minutes while the percentage of sperm properties increased. The progressive motility and total motility decreased from the concentration 0.5 mg / mL at times 30 and 60 minutes while the percentage of sperm immotile increased. The vitality (viable sperm) decreased significantly (p <0.05) from the exposure concentration 0.5 &#956;g/mL to 2,4-D and from 1.0 &#956;g/mL atrazine, at times 30 and 60 minutes, showing that there is a functional change of trend of human sperm after exposure to these herbicides, and this change is intensified with the exposure time factor and concentration of herbicides. Through the Raman Scaterring technique allowed us to characterize normal human sperm and exposed to herbicides and verify the change in the molecular structure in the exposed sperm, evidenced by changes in relative intensities of the bands 785, 1095, 1255, 1336, 1374, 1486 and 1575 cm-1 treated with 2,4-D and a decrease at 1095 after exposure to atrazine. These results indicate the modification of nitrogenous bases and the phosphate group that make up DNA present in the nucleus of the sperm. / A utilização desenfreada de praguicidas, além de contribuir com o agravamento da poluição ambiental, também está influenciando de forma negativa a saúde dos seres vivos, inclusive a saúde das pessoas. Muitos estudos mostram a interferência desses produtos químicos no sistema reprodutor de animais e até mesmo do homem, podendo acarretar problemas de infertilidade, que podem ser originados, dentre vários fatores, pela baixa quantidade e qualidade espermática. Este estudo visa á avaliação de parâmetros de qualidade espermática humana e a avaliação química do núcleo do espermatozoide, por meio de Espectroscopia de Espalhamento Raman, após a exposição in vitro a diferentes concentrações de ácido 2,4-diclorofenoxiacético (2,4-D) e atrazina. Estes herbicidas são amplamente utilizados em todo o mundo, principalmente no Brasil, em destaque a região do Oeste Paulista, por serem empregados na cana-de-açúcar, cultura significativa da região. Neste contexto, foram selecionadas amostras de espermatozoides de acordo com os parâmetros normais de testes que avaliam a qualidade espermática, como: liquefação, viscosidade, aparência, volume, pH, concentração de espermatozoides, vitalidade, morfologia e motilidade. Amostras de sêmen de 10 doadores saudáveis foram expostas aos herbicidas de estudo, variando o tempo e a concentração. Após as diferentes exposições (0,05; 0,5; 1,0; 5,0 e 125 &#956;g/mL, 30 e 60 min), as análises de motilidade e vitalidade foram novamente avaliadas. Os espectros de Espalhamento Raman foram obtidos das amostras de espermatozoide controle e após a exposição aos herbicidas 2,4-D e atrazina na concentração de 125 µg/mL em 60 min de incubação. A motilidade progressiva e motilidade total diminuíram a partir da concentração 0,5 &#956;g/mL nos tempos 30 e 60 min enquanto que a porcentagem de espermatozoides imóveis aumentou. A vitalidade (espermatozoides viáveis) diminuiu significativamente (p<0,05) a partir da exposição da concentração 0,5 &#956;g/mL para o 2,4-D e a partir de 1,0 &#956;g/mL para a atrazina, nos tempos 30 e 60min, mostrando-se que há uma tendência de alteração funcional do espermatozoide humano após a exposição a estes herbicidas, e esta alteração é intensificada com o fator de tempo de exposição e concentração dos herbicidas testados. Por meio da técnica de Espalhamento Raman foi possível caracterizar o espermatozoide humano normal e os expostos aos herbicidas e verificar a alteração na estrutura molecular nos espermatozoides expostos, evidenciadas pelas alterações nas intensidades relativas das bandas 785, 1095, 1255, 1336, 1374, 1486 e 1575 cm-1 do tratado com 2,4-D, e uma diminuição na banda de 1095 após a exposição à atrazina. Estes resultados indicam a alteração das bases nitrogenadas e do grupo fosfato que compõem o DNA presente no núcleo do espermatozoide.

Page generated in 0.0688 seconds