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Spermatozoa Isolated (spermatozoa + isolated)

Distribution by Scientific Domains

Medical Sciences	75%

Selected Abstracts

Interaction between leucocytes and human spermatozoa influencing reactive oxygen intermediates release

INTERNATIONAL JOURNAL OF ANDROLOGY, Issue 2 2004
Monika Fr
Summary The relationship between the presence of white blood cells (WBCs) and the fertilizing potential of human semen is still an open question. It is well known that the presence of leucocytes in human semen can be related to the production of reactive oxygen intermediates (ROI). Semen samples were obtained from 15 normozoospermic men and leucocytes were isolated from heparinized blood drawn from 15 volunteers. Lucigenin and luminol-mediated chemiluminescence assays were used to determine reactive oxygen species (ROS) generation by non-activated or activated leucocytes through 12-myristate-13-acetate or N-formyl-methionyl-leucyl-phenyalanine (FMLP) before the addition of spermatozoa isolated by swim-up or Percoll procedures. All spermatozoal fractions used in this study were characterized by defining their motility, morphology and viability. The levels of ROS formation by non-activated as well as stimulated leucocytes were significantly decreased after addition of swim-up separated spermatozoa (p < 0.01). The ability to inhibit the basal chemiluminescence was of lower degree for spermatozoa isolated from 90% Percoll fractions than for swim-up sperm. However, addition of sperm cells from 47% Percoll fraction was found to increase both lucigenin and luminol signals. Moreover, the determined ROI levels changed depending on the type of inducing factor used for oxidative burst. Then, spermatozoa selected by swim-up procedure although with only slightly higher viability and morphology than sperm obtained from 90% Percoll fraction clearly exhibited much higher capacity to inhibit ROI secretion by receptor-stimulated leucocytes (FMLP-activation) than Percoll fractionated sperm. Such results may indicate that within normal semen may exist sperm subpopulations with different biochemical mechanisms controlling the interaction between spermatozoa and contaminating leucocytes. When ROI levels contained in normozoospermic semen are dependent on the WBCs activation, it seems that spermatozoa with preserved normal functional competence are able to defend themselves against leucocytes-derived ROI. Also for normozoospermic ejaculates, swim-up sperm may improve semen antioxidant characteristics when comparing with Percoll (90%) separated sperm. It may help for optimal sperm preparation when assisting to infertility treatment. [source]

Superoxide dismutase content and fatty acid composition in subsets of human spermatozoa from normozoospermic, asthenozoospermic, and polyzoospermic semen samples

MOLECULAR REPRODUCTION & DEVELOPMENT, Issue 4 2003
J. Calamera
Abstract Human ejaculated sperm comprised discrete subsets of spermatozoa, with different degrees of maturation. These subpopulations can be isolated through density gradient centrifugation. Sperm from the lowest density layer show the highest content of docosahexaenoic acid and sterols, and produce the highest levels of reactive oxygen species. The main objective of this study was to determine the superoxide dismutase (SOD) content and fatty acid composition of subsets of spermatozoa isolated from normozoospermic, asthenozoospermic, and polyzoospermic semen samples. Four sperm fractions (1,4) were obtained using ISolate gradient centrifugation. Morphology, motion parameters, SOD content, and fatty acid composition were assessed in the original samples and their fractions. Overall, sperm from normozoospermic samples had higher SOD content than those of asthenozoospermic or polyzoospermic samples. Once fractionated in subsets, the sperm SOD content decreased significantly (P,<,0.0001) from fraction 1 (top) to 4 (bottom) in all three groups of samples. Fatty acid content as well as the oxidation coefficient followed the same pattern, decreasing from fraction 1 to 4 (F1,F4). Normo- and polyzoospermic samples showed similar amounts of fatty acids, while asthenozoospermic samples mostly revealed increased levels. Normozoospermic samples displayed the lowest unsaturated fatty acid (UFA)/SOD ratio. Spermatozoa from astheno- and polyzoospermic samples, two common seminal pathologies, showed higher UFA and lower SOD content than normal sperm, therefore exhibiting a higher susceptibility to peroxidative damage. F4 from all groups, containing the most mature spermatozoa, displayed the lowest polyunsaturated fatty acid and SOD content of all subsets, suggesting that excessive SOD activity as well as abundant peroxidative targets may both be deleterious to sperm function. Mol. Reprod. Dev. 66: 422,430, 2003. © 2003 Wiley-Liss, Inc. [source]

Effects of primary testicular damage on sperm DNA oxidative status and embryonic and foetal development

ANDROLOGIA, Issue 5 2009
F. Dimitriadis
Summary We evaluated the development of embryos generated from the fertilisation of oocytes with spermatozoa isolated from animals with primary testicular damage (PTD). Embryos derived in vivo or in vitro from oocytes fertilised with spermatozoa produced by PTD rats that had undergone surgical treatment for the PTD (group A1), or PTD rats (group A2), or control rats (group B) were cultured and transferred to recipients. At the end of the experimental period, the fertilisation potential of each rat was assessed in vitro (IVF trials). Sperm 8-oxodG/dG ratio (a marker of DNA oxidative status) was significantly larger in group A2 than in groups A1 and B. Blastocysts of the group A2 transferred to recipients demonstrated a significantly larger loss before implantation than transferred blastocysts of groups A1 or B. In addition, the proportion of implanted blastocysts that could not complete the intrauterine development was significantly larger in group A2 than in groups A1 and B. This study reveals a post-fertilisation detrimental effect in animals with PTD on the capacity of oocytes (fertilised either in vitro or in vivo) to develop in vitro and implant after transferring them to recipients probably attributable to sperm DNA oxidative damage. [source]

Protamine ratio and the level of histone retention in sperm selected from a density gradient preparation

ANDROLOGIA, Issue 2 2009
S. Hammoud
Summary Fertile males express two forms of sperm nuclear proteins, protamine 1 (P1) and protamine 2 (P2), in roughly equal quantities, whereas some infertile men have been shown to have a reduction in protamine content and an increase in the level of histones retained in mature sperm. In this study, we assessed histone and protamine levels in spermatozoa isolated from different layers of a density gradient centrifugation column to evaluate the nuclear protein content of the sperm population selected. Protamine levels were measured using acid gel electrophoresis and immunofluorescence, and the percentage of cells retaining histones was evaluated using aniline staining and immunofluorescence. Our data suggests that there is an inverse correlation between P1/P2 ratio and the level of histone expression in the different layers of the density gradient. Paradoxically, the 90% layer had a lower P1/P2 ratio, which corresponded with an increase in histone expression. It is concluded that although the sperm population selected in the 90% layer of the density gradient columns had a lower P1/P2 ratio, it was yet similar to the P1/P2 ratio observed in previously screened fertile donors. [source]