A series of experiments was conducted to examine potential toxic effects of cryoprotectants on motility of human spermatozoa. The data indicated that exposure of spermatozoa to cryoprotectant medium for as little as 15 minutes at room temperature caused a reduction in motility. This reduction in motility was caused by glycerol. Lowering glycerol concentrations from 7.5% to 5.0% improved sperm motility at 24 hours post-thaw. Sperm motility was not affected by either slow or abrupt cooling rates above -5 degrees C. Motility was greater in cryopreserved sperm at 24 hours post-thaw when glycerol was added at -5 degrees C rather than at room temperature. These data suggest that avoiding glycerol toxicity either by reducing the concentration used or by adding glycerol at a lower temperature, or both, may improve human sperm cryosurvival rates.
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Curr Top Dev Biol
January 2025
School of Molecular Biosciences, Washington State University, Pullman, Washington, United States. Electronic address:
For mammalian spermatogenesis to proceed normally, it is essential that the population of testicular progenitor cells, A undifferentiated spermatogonia (A), undergoes differentiation during the A to A1 transition that occurs at the onset of spermatogenesis. The commitment of the A population to differentiation and leaving a quiescent, stem-like state gives rise to all the spermatozoa produced across the lifespan of an individual, and ultimately determines male fertility. The action of all-trans retinoic acid (atRA) on the A population is the determining factor that induces this change.
View Article and Find Full Text PDFNucleic Acids Res
January 2025
Institute of Reproductive Medicine, School of Medicine, Nantong University, Nantong 226001, China.
Chromatin remodeling, which involves the histone-to-protamine exchange process during spermiogenesis, is crucial for sperm nuclear condensation and male fertility. However, the key regulators and underlying molecular mechanisms involved in this process remain largely unexplored. In this study, we discovered that deficiency in the family with sequence similarity 170 member A (Fam170a) led to abnormal sperm nuclear morphology and male infertility in mice, mirroring the observation of very low Fam170a transcription levels in sperm of infertile men with teratozoospermia.
View Article and Find Full Text PDFInt J Reprod Biomed
November 2024
Histomorphometry and Stereology Research Center, Anatomy Department, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
Background: In infertility clinics, long-time preserving high-quality spermatozoa is a challenging problem.
Objective: The present study aimed to prolong preserving of the human spermatozoa by adding pentoxifylline (PT) and L-carnitine (LC) without using high-cost freezing techniques.
Materials And Methods: In this experimental study, semen samples of 26 normozoospermia men aged between 28-34 yr, were firstly prepared using the swim-up technique, and each sample was divided into the following 3 aliquots: untreated control group, the LC, and PT-treated groups.
Reprod Biol Endocrinol
January 2025
Reproductive Medicine Center, Zhuhai Maternal and Child Health Care Hospital, 543 Ningxi Road, Zhuhai, 519000, China.
Purpose: Prior sperm DNA fragmentation index (DFI) thresholds for diagnosing male infertility and predicting assisted reproduction technology (ART) outcomes fluctuated between 15 and 30%, with no agreed standard. This study aimed to evaluate the impact of the sperm DFI on early embryonic development during ART treatments and establish appropriate DFI cut-off values.
Methods: Retrospectively analyzed 913 couple's ART cycles from 2021 to 2022, encompassing 1,476 IVF and 295 ICSI cycles, following strict criteria.
Nutrients
January 2025
ART and Reproductive Biology Laboratory, University Hospital and School of Medicine, Picardie University Jules Verne, CHU Sud, 80000 Amiens, France.
Today, accumulating evidence highlights the impact of oxidative stress (OS) on semen quality. It is considered to be a key factor contributing to the decline in male fertility. OS is detected in 30-80% of men with infertility, highlighting its strong association with impaired reproductive function and with clinical outcomes following the use of assisted reproductive technologies.
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