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Background: The influence of ejaculatory abstinence (EA) on semen parameters and subsequent reproductive outcome is still debatable; hence understanding the impact of EA on sperm structural and functional integrity may provide a valuable information on predicting successful clinical outcome., Objective: To understand the influence of EA on sperm chromatin maturity, integrity, longevity and global methylation status., Methods: This experimental prospective study included 76 ejaculates from 19 healthy volunteers who provided ejaculates after observing 1, 3, 5 and 7 days of abstinence. Sperm chromatin maturity, DNA integrity and global methylation status were assessed in the neat ejaculate. Sperm motility, DNA integrity and longevity were assessed in the processed fraction of the fresh and frozen-thawed ejaculates to determine their association with the length of EA., Results: Spermatozoa from 1 day ejaculatory abstinence (EA-1) displayed significantly higher level of sperm chromatin immaturity in comparison to EA-3 (P < 0.05) and EA-5 (P < 0.01) whereas; the number of 5-methyl cytosine immunostained spermatozoa did not vary significantly across groups. On the other hand, in vitro incubation of processed ejaculate from EA-1 resulted in approximately 20 and 40 fold increase in the DNA fragmented spermatozoa at the end of 6 and 24h respectively (P < 0.01-0.001)., Conclusion: Use of short-term EA for therapeutic fertilization would be a clinically valuable strategy to improve the DNA quality. However, use of such spermatozoa after prolonged incubation in vitro should be avoided as it can carry a substantial risk of transmitting DNA fragmentation to the oocytes.

To differentiate dead spermatozoa from viable but immotile spermatozoa, several techniques are being used during ICSI. As processed spermatozoa from poor-quality ejaculate are confronted with a higher risk of experiencing stress on exposure to altered osmotic conditions or chemicals, this study was undertaken to determine the expression of stress response gene Hsp70 and chromatin integrity in spermatozoa subjected to in situ viability assays such as hypo-osmotic swelling (HOS) test, modified hypo-osmotic swelling (M-HOS) test and pentoxifylline in 25 fresh and frozen-thawed asthenozoospermic ejaculates. RT-PCR and immunofluorescence detection of Hsp70 were performed to elucidate the expression and localisation of Hsp70 in spermatozoa, whereas DNA fragmentation analysis was performed by sperm chromatin dispersion assay. Exposure of fresh and frozen-thawed asthenozoospermic spermatozoa to M-HOS and pentoxifylline significantly increased Hsp70 expression as evidenced by increased RNA expression and immunolocalisation of Hsp70 protein in sperm head (P < 0.05-0.001). However, chromatin integrity was not significantly affected in any groups until 6 h of post-exposure time period. Our results suggest that conventional HOS may be preferred for the in situ detection of the viability as there was no immediate stress response and chromatin instability in the exposed spermatozoa., (© 2014 Blackwell Verlag GmbH.)

There is a paucity of data regarding the association between occupational radiation exposure and risk to human fertility. Recently, we provided the first evidence on altered sperm functional characteristics, DNA damage and hypermethylation in radiation health workers. However, there is no report elucidating the association between seminal plasma antioxidants and sperm chromatin integrity in occupationally exposed subjects. Here, we assessed the seminal plasma antioxidants and lipid peroxidation level in 83 men who were occupationally exposed to ionizing radiation and then correlated with the sperm chromatin integrity. Flow cytometry based sperm chromatin integrity assay revealed a significant decline in αt value in the exposed group in comparison to the non-exposed group (P<0.0001). Similarly, both total and reduced glutathione levels and total antioxidant capacity in the seminal plasma were significantly higher in exposed group than the non-exposed group (P<0.01, 0.001 and 0.0001, respectively). However, superoxide dismutase level and malondialdehyde level, which is an indicator of lipid peroxidation in the seminal plasma, did not differ significantly between two groups. The total antioxidant capacity (TAC) and GSH level exhibited a positive correlation with sperm DNA integrity in exposed subjects. To conclude, this study distinctly shows that altered sperm chromatin integrity in radiation health workers is associated with increase in seminal plasma antioxidant level. Further, the increased seminal plasma GSH and TAC could be an adaptive measure to tackle the oxidative stress to protect genetic and functional sperm deformities in radiation health workers., (Copyright © 2014 Elsevier Inc. All rights reserved.)