Exogenous Oxidative Stress in Human Spermatozoa Induces Opening of the Mitochondrial Permeability Transition Pore: Effect on Mitochondrial Function, Sperm Motility and Induction of Cell Death.

Oxidative stress (OS) and disrupted antioxidant defense mechanisms play a pivotal role in the etiology of male infertility. The alterations in reactive oxygen species (ROS) production and calcium (Ca) homeostasis are the main activators for the mitochondrial permeability transition pore (mPTP) opening. The mPTP opening is one of the main mechanisms involved in mitochondrial dysfunction in spermatozoa.

Transmission electron microscopy reveals the presence of SARS-CoV-2 in human spermatozoa associated with an ETosis-like response.

Background: Severe acute syndrome coronavirus 2 can invade a variety of tissues, including the testis. Even though this virus is scarcely found in human semen polymerase chain reaction tests, autopsy studies confirm the viral presence in all testicular cell types, including spermatozoa and spermatids.

Objective: To investigate whether the severe acute syndrome coronavirus 2 is present inside the spermatozoa of negative polymerase chain reaction-infected men up to 3 months after hospital discharge.

Human sperm vitrification: A scientific report.

Background: The sperm vitrification developed by this group is based on the ultrarapid freezing of a vitrification solution composed of a non-permeable cryoprotectant (saccharides and protein), in which previously selected spermatozoa are resuspended, free of seminal plasma, and then plunged directly into liquid nitrogen. Compared to traditional sperm freezing, vitrification does not cause chemical or physical damage to the intracellular structures and reduces the damage to the plasma membrane because no ice crystals form, thus preserving motility and DNA integrity.

Objectives: This manuscript is a review of the vitrification methodology developed by the authors' research group, including studies showing the application in human reproduction therapy.

Preservation of boar semen: An update.

In the pork industry, artificial insemination and the storage of boar semen in liquid at 17°C are routinely applied to optimize the ejaculate and bring about rapid genetic changes that are reflected in the animal protein. Although the results are satisfactory, they are below what occurs with natural mating. It is currently possible to preserve boar semen with storage at 17°C and slow freezing, since to date there is only one study on vitrification, with negative results applicable only in the case of implementing an intracytoplasmic sperm injection.