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Effect of three cryoconservation diluents on sperm motility and vitality in the ejaculate of bulbourethal-ectomized llamas (Lama glama), department of La PazMaceda Tintaya, Edwin Eddy 01 January 2008 (has links) (PDF)
The purpose of this study was to evaluate the effects of three different diluents used during the cryopreservation process on the motility and vitality of sperm cells. The three diluters used in this study were: A) trice-serum-egg yolk-glycerin, B) serum-egg yolk-glycerin, and C) Dulbecco’s serum-egg-yolk- glycerin. Diluters were tested in proportions of 64-15-15-6% (N1), 54-20-20-6% (N2), and 44-35-15-6% (N3). Llama semen was collected at the Mejoramiento Genético y Diagnóstico Clínico Del Servicio Agropecuario (SEDAG) in the Los Andes Province of the Department of La Paz. The procedure took place at the Unidad Académica Campesina de Tiahuanaco by a direct optimized bulbourethral collection method with an artificial vagina.
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Metabolomics of Human Semen: A Review of Different Analytical Methods to Unravel Biomarkers for Male Fertility DisordersBlaurock, Janet, Baumann, Sven, Grunewald, Sonja, Schiller, Jürgen, M. Engel, Kathrin 05 December 2023 (has links)
Background: Human life without sperm is not possible. Therefore, it is alarming that the
fertilizing ability of human spermatozoa is continuously decreasing. The reasons for that are widely
unknown, but there is hope that metabolomics-based investigations may be able to contribute to
overcoming this problem. This review summarizes the attempts made so far. Methods: We will
discuss liquid chromatography–mass spectrometry (LC-MS), gas chromatography (GC), infrared (IR)
and Raman as well as nuclear magnetic resonance (NMR) spectroscopy. Almost all available studies
apply one of these methods. Results: Depending on the methodology used, different compounds
can be detected, which is (in combination with sophisticated methods of bioinformatics) helpful
to estimate the state of the sperm. Often, but not in all cases, there is a correlation with clinical
parameters such as the sperm mobility. Conclusions: LC-MS detects the highest number of metabolites and can be considered as the method of choice. Unfortunately, the reproducibility of some
studies is poor, and, thus, further improvements of the study designs are needed to overcome this
problem. Additionally, a stronger focus on the biochemical consequences of the altered metabolite
concentrations is also required
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Cryopreservation of microencapsulated bovine spermatozoaPandolfi, Susan M. 01 November 2008 (has links)
The ultimate design of a microencapsulated AI dose is to continuously release sperm over a period of time in the female reproductive tract, thus alleviating the need for estrus detection. The objective of Trial 1 was to determine in vitro sperm release times for three microcapsule membranes. Semen was collected from four bulls, pooled, extended in 20% egg yolk TEST to a concentration of 80 = 10⁶ cells/ml, and encapsulated. Microcapsule membranes were constructed from isomers of polylysine: .1% poly-L-lysine (PLL), .1% poly-D-lysine (PDL), and a 50:50 mixture of the isomers (PLPD). Microcapsules were incubated at 37°C in a buffer containing .5% heparin or .5% trypsin and evaluated at 0.5, 1, 2, 4, 8, and 16 h post-encapsulation. For sperm encapsulated there were no significant differences in sperm motility. However, peak time of maximum sperm release differed between PLL and PDL membranes at 2 and 4 h of incubation. In Trial 2, sperm viability and microcapsule membrane stability were assessed post-thaw using PLL or PDL, two encapsulating temperatures (5°C or 23°C) and two times of glycerol addition (prior or post encapsulation at 5°C). Semen was extended to 80 = 10⁶ cells/ml and encapsulated. Capsules from all treatment combinations were incubated in .5% trypsin and evaluated as in Trial 1. In addition, motility was estimated at 1, 3, 6, and 9 h post-thaw. Motility from the unencapsulated control and capsules with glycerol addition prior to encapsulation, was superior (P < .05). Additionally, sperm release from capsules prepared at 5°C with glycerol addition post encapsulation was greater than all other treatments (P < .05). Time of peak sperm release for capsules was similar to the previous trial. There was a positive correlation between average capsule diameter and sperm release for both trials (P < .05). These data suggest that a combination of PLL and PDL capsules may complement each other in timing of sperm release and may be utilized in an inseminate mixture for extending the effective release in the female / Master of Science
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Effect of high and low dosage of fresh and frozen semen on accessory sperm number, fertility and embryo quality in artificially inseminated cattleNadir, Sher 22 October 2009 (has links)
This study was designed to : 1) Determine the effects of fresh vs frozen semen at a high inseminate dosage (lOOxl06sperm) contrasted to their effects at a conventional dosage (20xl06 sperm) on accessory sperm per ovum and 2) Evaluate the relationship between accessory sperm number per embry%vum and fertilization status/embryo quality if accessory sperm number were affected by treatment. In this study semen from four bulls routinely giving a minimum of 700/0 morphologically normal and 600/0 motile sperm cells were used. Ejaculates of these bulls were split and prepared for use as fresh and frozen semen at either 100xl06 or 20xI06 cells per dose in.5 mL French straws. Half of the total semen filled straws were frozen in liquid nitrogen at -196°C and half were stored at 5°C for 4 days after collection and used as unfrozen. Cows in standing heat were inseminated with fresh or frozen semen at either high (IOOxl06 sperm) or conventional dose (20xl06 sperm).
Ova/embryos were recovered non surgically on day 6 after breeding. Accessory sperm were counted in the recovered embryos/ova after partial digestion with Pronase followed by compression of the embryo/ovum with a cover slip. From 129 inseminations to normally cycling cows, 98 embryos/ova were recovered. To reduce male effects, embryos/ova used were randomly balanced across treatments, by ejaculate within bull for evaluation of frozen vs fresh semen (n = SO) and by bull for evaluation of high vs low dosage treatments (n = 76). No difference (P > 0.05) in accessory sperm was observed for fresh vs frozen semen at either the high or low dosage. The mean accessory sperm values for fresh high dose (n=21), frozen high dose (n=21), fresh low dose (n= 19), and frozen low dose (n= 19) were 26.S1±30.23 (SD), 36.05±44.74 (SD), 29.37± 55.97 (SD) and 30.l6± 70.18 (SD) respectively. When data for embryos/ova resulting from fresh and frozen semen were pooled within dosage, a significant difference was observed between the median accessory sperm values for high and low doses of semen (P < .05). Mean ± SD and median values for accessory sperm were: 37.8± 38.3 and 27.5; 28.9± 62.8 and 3.0, for the high and low dose, respectively. Increasing accessory sperm number by the higher dosage improved the fertilization status/embryo quality (P < .05). Percentage unfertilized ova, degenerate embryos and embryos classified poor to fair and good to excellent were: 3, 5, 24, 68; and 21, 16, 18, 45, for the high and low dose, respectively. Overall, embryos/ova classified good to excellent, poor to fair, degenerate and unfertilized had median accessory sperm values of 18, 9.5, 5.5 and 0, respectively. However, the lack of accessory sperm in unfertilized ova was significantly different from excellent-good quality embryos (P < .05). / Master of Science
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The Effect of Poly-L-Lysine Concentration, Molecular Weight, and Encapsulation Temperature on Microencapsulated Bovine SpermatozoaFultz, Stanley Wakefield 29 July 2013 (has links)
A series of in vitro studies were conducted to evaluate the effect of poly-l-lysine concentration, molecular weight, and encapsulation temperature on the post encapsulation survivability of spermatozoa. Viability of spermatozoa encapsulated at 2012 C using four poly-l-lysine concentrations (.05%, .15%, .25%, and .35%) did not differ over the 8 h incubation period. However, the viability of each of the four treatments was lower than that of the unencapsulated control (p<.05 and p<.01; percentage motility and percentage intact acrosomes, respectively), indicating spermatozoal damage occurred during the encapsulation process. Capsule wall thickness and integrity for the .15%, .25%, and .35% concentrations were greater (p<.Ol) than that of the .05% capsules. / Master of Science
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Experiments to improve the quality of sex-sorted fresh and frozen porcine spermatozoa / Experimente zur Verbesserung der Qualität von gesextem und tiefgefrorenem EberspermaGroßfeld, Rudolf 16 May 2007 (has links)
No description available.
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Improvements in the viability and fertilizing integrity of boar spermatozoa using the "umqombothi" sorghum bicolour semen extendersPitso, Teele January 2009 (has links)
Thesis (M. Tech. (Agric. Animal Prod.)) -- Central University of technology, Free State, 2009 / The objective of this study was to evaluate the viability of semen extended in “Umqombothi” (UMQ) and compare with Beltsville Thawing Solution (BTS) and unextended semen (UNX). Twelve large white boars and twelve large white sows were used in this experiment. The following sperm characteristics were measured; sperm motility percentage, live sperm, sperm concentration, abnormal sperm percentage and semen pH of (UNX), (UMQ) and (BTS) and compared, fertility parameters namely; non-return rate percentage, farrowing rate, total piglets and live piglets were also measured and compared.
The results from the study showed a significant difference (p<0.05) in sperm motility between (UNX), (UMQ) and (BTS) whereby (UMQ) had the highest percentage of motile sperm which was followed by (BTS) and (UNX) having the lowest percentage of motile sperm, however the results also showed that sperm motility and live sperm percentage of semen stored at 4°C differed significantly (p<0.05) from sperm motility and live sperm percentage of semen stored at 25°C whereby sperm motility and live sperm percentage of semen stored at 25°C were higher than sperm motility and live sperm percentage of semen stored at 4°C. Nevertheless no significant difference in sperm concentration and semen pH was found when semen stored at 4°C and 25°C were compared. However were time of semen collection of 9:00 and 15:00 were compared no significant differences in sperm motility percentage, live sperm percentage, sperm concentration, abnormal sperm percentage and semen pH were observed.
The study also revealed a significant difference (p<0.05) in non-return rate, farrowing rate, total piglets and live piglets between semen stored at 25°C and 4°C of which the results explain that semen stored at 25°C had a higher percentage of non-return rate , farrowing rate, total piglets and live piglets, however, Under (UNX) collected at 9:00 and 15:00 that there was no significant difference in no-return rate percentage, farrowing rate, total piglets and live piglets was observed when two times of semen collections were compared. Under (UMQ) collected at 9:00 and 15:00 there was also no significant difference in non-return rate percentage, farrowing rate, total piglets and live piglets observed when two times of semen collections were compared. Under (BTS) collected at 9:00 and 15:00 there was also no significant difference in non-return rate percentage, farrowing rate, total piglets and live piglets observed when two times of semen collections were compared. Nevertheless were semen extenders were compared (UNX) collected at 9:00 and 15:00 differed significantly (p<0.05) from (UMQ) and (BTS) collected at 9:00 and 15:00 whereby (UNX) had the lowest percentage of non-return rate, farrowing rate, total piglets and live piglets.
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Predictive value of normal sperm morphology in intrauterine insemination (IUI) : a structured literature reviewVan Waart, J. (Johannes) 12 1900 (has links)
Thesis (MMed)--Stellenbosch University, 2001. / ENGLISH ABSTRACT: The aim of the study was to conduct a structured review of the literature published on the
use of normal sperm morphology, as an indicator of male fertility potential in intrauterine
insemination (M) programs. Published literature in which normal sperm morphology
was used to predict pregnancy outcome in lUI during the period 1984 - 1998 was
reviewed.
Four hundred and twenty one articles were identified. Eighteen provided data that could
be tabulated and analyzed. Eight of the analyzed studies provided sufficient data for
statistical analysis. Six studies used the Tygerberg strict criteria and two the WHO
guidelines (1987, 1992). A meta-analysis of the six studies in the strict morphology
group yielded a risk difference (RD) between the pregnancy rates achieved in the patients
below and above the 4% strict criteria threshold of -0.07 (95% CI: -0.11 to -0.03;
p< 0.001). WHO criteria group (1987,1992) had insufficient data to be analysed.
Meta-analysis showed a significant improvement in pregnancy rate above 4% threshold
for strict criteria. Accurate evaluation of normal sperm morphology results should be an
integral part of evaluating the male factor. / AFRIKAANSE OPSOMMING: Die doel van die studie was om 'n gestruktureerde literatuuroorsig van die gepubliseerde
data oor normale sperm morfologie uit te voer om vas te stelof dit enige waarde het as
voorspeller van manlike fertiliteitspotensiaal in intra uteriene inseminasie (lUI)
programme. Gepubliseerde literatuur waar normale sperm morfologie gebruik IS om
swangerskapsuitkoms te voorspel met IUI in die tydperk 1984 - 1998 is nagegaan.
Vierhonderd een en twintig artikels is geïdentifiseer. Agtien het genoeg data gehad om te
kan tabuleer en analiseer. Agt van die geanaliseerde studies het voldoende data gehad vir
statistiese analise. Ses studies het die Tygerberg streng kriteria gebruik en twee die WGO
(1987, 1992) riglyne. 'n Meta-analise van die ses studies in die streng kriteria groep het
'n risiko verskil tussen swangerskapstempo in pasiënte onder en bo die 4% streng kriteria
afsnypunt, van -0,07 (95% betroubaarheidsindeks: -0.11 tot -0.03; p<O.OOl) getoon.
Die WGO kriteria (1987,1992) groep het onvoldoende data gehad om te kan analiseer.
Meta-analise het 'n bekenisvolle verbetering in swangerskapuitkoms bo die 4% afsnypunt
getoon vir die streng kriteria. Akkurate evaluasie van normale sperm morfologie
resultate behoort 'n integrale deel te wees van die proses om die manlike faktor in
infertilteitsbehandeling volledig te evalueer.
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Effects of insulin and leptin on human spermatozoa function and their cross-talk with nitric oxide and cytokinesLampiao, Fanuel 12 1900 (has links)
Thesis (PhD (Biomedical Sciences. Medical Physiology))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: In recent years there has been an increase in obesity and diabetes mellitus (DM).
These conditions have for a long time been associated with infertility. Obesity is
characterized by high levels of circulating leptin and cytokines as well as insulin
resistance. Type I DM is associated with low or no insulin whereas, Type II DM is
characterised by insulin resistance. As the prevalence of obesity and DM continues
to rise, it is likely that the incidence of infertility associated with these pathological
conditions will likewise increase. The effects of insulin and leptin on male
reproductive function have been reported on the endocrine and spermatogenesis
level, but their effects on cellular level of human ejaculated spermatozoa are yet to
be elucidated.
This study presents data on the role of insulin and leptin on human ejaculated
spermatozoa and their interaction with cytokines and nitric oxide. In the first part of
the study, we established the suitable concentrations of glucose, insulin and leptin
that could be administered to human spermatozoa in vitro. Glucose concentration of
5.6 mM was chosen as the suitable concentration to be administered to human
spermatozoa because it has previously been reported in the literature; furthermore, it
is within the range of the physiological glucose levels found in the blood of fasting
humans. Insulin and leptin concentrations of 10 μIU and 10 nmol were chosen
respectively because they gave much improved sperm function and this was within
the range of insulin and leptin levels previously measured in human ejaculated
spermatozoa. This was followed by investigating the signalling pathway of insulin and
its beneficial effects on human spermatozoa function. Endogenous insulin secretion
from human ejaculated spermatozoa was blocked by nifedipine and its receptor
tyrosine phosphorylation effects were inhibited by erbstatin while phosphatidylinositol
3-kinase (PI3K) phosphorylation activity was inhibited by wortmannin. Exogenous
insulin administration significantly increased human sperm motility parameters as
well as the sperm ability to acrosome react. The inhibition of endogenous insulin
release from spermatozoa as well as the inhibition of the insulin receptor substrate
(IRS) tyrosine phosphorylation significantly decreased motility parameters and the
ability of spermatozoa to acrosome react.
The study also investigated the effects of insulin and leptin on human sperm motility,
viability, acrosome reaction and nitric oxide (NO) production. Both insulin and leptin
significantly increased sperm motility parameters, acrosome reaction and NO
production. The NO production induced by insulin and leptin was via PI3K signalling
as evidenced by a reduction in NO levels when PI3K activity was inhibited by
wortmannin. To investigate whether insulin and leptin could improve motility
parameters of asthernozoospermic and teratozoospermic spermatozoa, the
spermatozoa were separated into two fractions by means of a double density
gradient technique. The gradient system was able to separate spermatozoa into high
morphologically abnormal and less motile spermatozoa similar to that of
asthernozoospermic and teratozoospermic patients as well as a more motile fraction.
Insulin and leptin significantly increased the motility parameters of spermatozoa from
the immature and less motile fraction.
The fourth part of the study was aimed at investigating the effects of the cytokines,
tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6), on human sperm
motility, viability, acrosome reaction and NO production. The study shows that TNF-α
and IL-6 significantly reduced motility parameters and acrosome reaction in a dose4
and time-dependent manner. These cytokines were also shown to significantly
increase NO production from human spermatozoa. The decreased motility
parameters induced by these cytokines could be attributed to their ability to induce
excessive NO production. It is not yet clear how they inhibit spermatozoa to undergo
the acrosome reaction.
The fifth part of the study was to investigate the expression and localization of
glucose transporter 8 (GLUT8) in human spermatozoa. This study shows that GLUT8
is constitutively expressed and located in the midpiece region of the human
spermatozoa. The study also showed that stimulating spermatozoa with insulin led to
an increase in GLUT8 expression as well as translocation to the acrosomal region.
In the last part of the study we wanted to investigate why the increase in NO
generation by spermatozoa due to insulin and leptin stimulation is accompanied with
increased sperm function whereas NO increased due to TNF-α and IL-6 stimulation
is accompanied with decreased sperm function. We observed that TNF-α and IL-6
not only increased NO production but also ROS production. This study speculates
that the decrease in sperm motility and acrosome reaction when TNF-α and IL-6
were administered was due to the concomitant high increase in NO and ROS they
induced.
In conclusion, this study has established in vitro beneficial effects of insulin and leptin
in normozoospermic and asthernozoospermic human sperm function. These
hormones influence sperm function via the PI3K signalling pathway in two ways.
Firstly, by increasing GLUT8 expression and translocation thereby possibly
increasing glucose uptake and metabolism and secondly, by increasing NO
production. The study has also established that TNF-α and IL-6 have detrimental
effects on human spermatozoa in a dose and time dependent manner. These effects
are mediated via their ability to stimulate both NO and ROS production in human
spermatozoa. This study reports that GLUT8 is expressed in the midpiece region of
human spermatozoa and that insulin stimulation upgrades its expression and leads to
its translocation to the acrosomal region. / AFRIKAANSE OPSOMMING: Oor die afgelope jare was daar `n toename in obesiteit en diabetes mellitus (DM).
Hierdie toestande word reeds vir ’n geruime tyd geassosieer met onvrugbaarheid.
Obesiteit word gekenmerk deur verhoogde sirkulerende vlakke van leptiene en
sitokiene sowel as insulien weerstandigheid. Tipe I DM word geassosieer met lae of
geen insulien terwyl Tipe II DM gekenmerk word deur insulien weerstandigheid. Soos
wat die voorkoms van obesiteit en DM toeneem, is dit waarskynlik dat die insidensie
van onvrugbaarheid wat met hierdie patologiese toestande geassosieer word,
gevolglik ook sal toeneem. Die effek van insulien en leptien op die manlike
voortplantingsfunksie is alreeds aangetoon op endokriene en spermatogenese vlak,
maar hul effekte op sellulêre vlak van menslike geëjakuleerde spermatosoë is nog
onduidelik.
Die studie vertoon data oor die rol van insulien en leptien op die menslike
geëjakuleerde spermatosoë en hul interaksie met sitokiene en stikstofoksied (NO). In
die eerste gedeelte van die studie, het ons ’n toepaslike konsentrasie van insulien en
leptien bepaal wat aan menslike spermatosoë in vitro toegedien kan word. Glukose
konsentrasies van 5,6 mM is bepaal as die gepaste konsentrasie om aan menslike
spermatosoë toe te dien, omdat dit beter resultate tot gevolg het; verder is dit
vergelykbaar met fisiologiese glukose vlakke in die bloed van `n vastende persoon.
Insulien en leptien konsentrasies is op 10 μIU en 10 nm onderskeidelik vasgestel,
aangesien dit tot beter resultate gelei het, en omdat dit vergelykbaar was met
insulien en leptien vlakke wat reeds voorheen in menslike geëjakuleerde
spermatosoë gemeet is. Dit was gevolg deur `n ondersoek na die insulien
seintransduksie pad en sy voordelige effekte op menslike spermatosoë funksie.
Endogene insulien afskeiding deur menslike geëjakuleerde spermatosoë was deur
nifedipien geïnhibeer en sy reseptor tirosien fosforilasie effekte was deur erbstatin
geïnhibeer terwyl fosfatidielinositol 3-kinase (PI3K) fosforilasie deur wortmannin
geïnhibeer is. Eksogene insulien toediening het menslike sperm-motiliteit parameters
betekenisvol laat toeneem asook die vermoë van sperme om die akrosoomreaksie te
ondergaan. Die inhibisie van endogene insulien afskeiding deur spermatosoë sowel
as die inhibisie van die insulien reseptor substraat (IRS) tirosien fosforilasie het die
motiliteit parameters en die akrosoomreaksievermoë van spermatosoë verlaag.
Die studie het ook die effekte van insulien en leptien op menslike sperm-motiliteit,
-lewensvatbaarheid, -akrosoomreaksie en -NO produksie nagevors. Beide insulien
en leptien het sperm-motiliteit parameters, -akrosoomreaksie en -NO produksie
betekenisvol verhoog. NO produksie is deur insulien en leptien via PI3K
seintransduksie geïnduseer, soos bewys deur die verlaging waargeneem in NO
vlakke toe PI3K aktiwiteit deur wortmannin geïnhibeer was. Om vas te stel of insulien
en leptien die motiliteit parameters van asthenozoospermiese en teratozoospermiese
spermatosoë kon verbeter, het ons spermatosoë in twee fraksies met ’n dubbel
digtheid gradiënt geskei. Die gradiënt sisteem was daartoe instaat om die
spermatosoë in ’n onvolwasse, (morfologies abnormaal en minder motiel - soortgelyk
aan dié van asthenozoospermiese en teratozoospermiese pasiënte), sowel as ’n
volwasse meer motiele fraksie te skei. Insulien en leptien het die motiliteit parameters
van spermatosoë van die onvolwasse en minder motiele fraksie verhoog.
Die vierde gedeelte van die studie was daarop gemik om die effekte van die sitokiene
tumor nekrose faktor alfa (TNF-α) en interleukin-6 (IL-6) op menslike sperm-motiliteit,
-lewensvatbaarheid, -akrosoomreaksie en -NO produksie, te ondersoek. Die studie
het getoon dat TNF-α en IL-6 motiliteit parameters en akrosoomreaksie in ’n tyd- en
dosis-afhanklike wyse betekenisvol verlaag het. Hierdie sitokiene was ook in staat
om NO produksie in menslike spermatosoë te verhoog. Die verlaging in motiliteit
parameters wat deur hierdie sitokiene geïnduseer is, kan toegeskryf word aan hul
vermoë om die produksie van oormatige hoeveelhede NO te stimuleer. Dit is nog nie
duidelik hoe hulle die akrosoomreaksie in spermatosoë kan inhibeer nie.
Die vyfde gedeelte van die studie het dit ten doel gehad om die uitdrukking en
lokalisering van die glukose transporter 8 (GLUT8) in menslike spermatosoë te
ondersoek. Hierdie studie kon aantoon dat GLUT8 konstitutief uitgedruk is en in die
middelstuk van die menslike spermatosoë voorkom. Die studie bewys ook dat
stimulering van die spermatosoë met insulien tot `n toename in GLUT8 uitdrukking
sowel as translokasie na die akrosomale area, lei.
In die finale gedeelte van die studie wou ons ondersoek waarom die toename in NO
produksie in spermatosoë (as gevolg van insulien en leptien stimulasie) deur `n
toename in spermfunksie gekenmerk word, terwyl die toename in NO produksie (as
gevolg van TNF-α en IL-6 stimulasie) deur ’n afname in spermfunksie gekenmerk
word. Ons het waargeneem dat TNF-α en IL-6 nie alleen NO produksie nie, maar ook
reaktiewe suurstof spesies (ROS) produksie verhoog het. Ons vermoed dat die
afname in sperm motiliteit en akrosoomreaksie met TNF-α en IL-6 toediening, die
gevolg van die gelyktydige verhoging in NO en ROS was.
In gevolgtrekking kan ons sê dat hierdie studie die voordelige in vitro effekte van
insulien en leptien op asthenozoospermiese en teratozoospermiese menslike
spermfunksie aangetoon het. Hierdie hormone beïnvloed spermfunksie via die PI3K
seintransduksie pad op twee maniere. Eerstens, deur `n toename in GLUT8
uitdrukking en translokasie, met die gevolg dat glukose opname en metabolisme
moontlik verhoog is, en tweedens, deur die toename in NO produksie. Die studie het
ook vasgestel dat TNF-α en IL-6 nadelige effekte op menslike spermatosoë in `n
dosis- en tyd-afhanklike wyse het. Hierdie effekte vind plaas a.g.v. hul vermoë om
beide NO en ROS produksie in menslike spermatosoë te induseer. Die studie toon
aan dat GLUT8 uitdrukking in die middelstuk van die menslike spermatosoon
voorkom en dat insulien stimulasie GLUT8 uitdrukking opreguleer en tot translokasie
na die akrosomale area lei.
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The interaction between human spermatozoa and its homologous zona pellucida : scientific advances and clinical significanceOehninger, Sergio C. 12 1900 (has links)
Thesis (PhD)--Stellenbosch University, 2002. / ENGLISH ABSTRACT: Infertility is a very common problem worldwide. Recent data have shown that disorders of the
male represent the most common single defined cause of infertility. This proposal examines
the clinical significance and fundamental physiological aspects of human gamete interaction.
These studies are focused on the assessment of the cellular-molecular mechanisms involved in
human sperm binding to its homologous zona pellucida resulting in the physiologic induction
of the acrosome reaction. We have developed and validated in vitro bioassays that assess
specific steps of the fertilization process that are critical for early embryo development. The
results of our translational research have already had a significant impact on the overall
evaluation of male infertility and on the clinical management of the infertile man in the
assisted reproduction arena. Furthermore, the unveiling of the basic mechanisms involved in
human gamete interaction will ultimately allow for both (i) the development of new male
reproductive diagnostic capabilities and (ii) the design of improved and safer therapies aiding
conception in childless couples suffering from male infertility. / AFRIKAANSE OPSOMMING: Menslike onvrugbaarheid is 'n algemene wêreldwye probleem en onlangse data toon aan dat
die manlike factor die grootste enkel bydraende factor tot hierdie toestand is. Die werk loods
'n intensiewe ondersoek na die kliniese betekenis en basiese fisiologiese aspekte wat 'n rol
tydens spermsel en eisel interaksie speel. Hoofstuk 3 fokus op die sellulêre en molekulêre
meganismes wat betrokke is tydens spermsel en eisel binding wat gevolglik lei tot
akrosoomreaksie van die spermsel. Die werk verteenwoordig die resultate van 10 jaar se
navorsing tussen die kandidaat en die promoter. Dit gee oorsprong aan 'n reeks bio-toetse wat
die bevrugtingsproses koriografiese ontleed en verskaf dus 'n stap-vir-stap uiteenseting van
menslike bevrugting en gevolglike embrio ontwikkeling. Die resultate in Hoostuk 4 bring
vernuwing in die begrippe van die manlike faktor en die rol in die kinderlose huwelik. Die
resulate soos in Hoofstuk 3 en 4 uiteengesit, vorm nie net die basis vir die moontlike
ontwikkeling van nuwe diagnostiese benaderings tot die hantering van die man nies maar
speel oojk 'n rol die daarstelling van verbeterde terapeutiese hantering van die kinderlose
egpaar. Hoofstuk 5 gee kortliks riglyne en aanbevelings tot opsigte van die gebruik van die
spermsel-zona pellucida bindingstoets en akrosomreaksie. Die kandidaat bevel aan dat die
genoemde twee bio-toetse deel van die laboratorium ondersoeke van die man gebruik moet
word.
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