Ciência e Tecnologia Veterinária

The Restraint of Bovine Sperm Cell Motility Increases Survival: Role of Extracellular Calcium in the Phenomena

Abstract

Ian Scott, Alfredo Ramirez-Reveco and Jorge Parodi*

Sperm cells are complex models for handling in vitro, their viability is limited, and their physiology is complex. The study of their properties is of great application in the animal production industry, to improve the selection of gametes, control pathologies and for the development of cryobiology protocols. It is therefore important to have viable and functional gametes. Consequently, it has been demonstrated that the increase of sperm cell mortality is related to the increase of the Reactive Oxygen Species (ROS), and ROS is secondary to normal metabolic processes of the cell, i.e., special motility. One of the processes where the mature sperm cells’ main activity is the consumption of more energy, it is the flagellar movement through which high ATP consumption generates high quantities of ROS in the seminal plasma. There is evidence of strategies that lead to reduced metabolic activity for different variables (temperature, pH and other), the intention being that seminal plasma protects the sperm cells and reduces the mortality, and thus it is correct to suggest reducing mortality by reducing motility. It has to be considered that flagellar movement is a complex action that involves energy consumption, regulated by calcium. The phenomenon has not been fully characterized, but it is established that in certain mammalian models, the entry of calcium in specific channels such as CATsper or voltage-dependent channels is a signal for flagellar movement to occur. Reduce the motility of bovine spermatozoa using calcium channel blockers can increase cell survival and we hypothesized that: the general blockade of the calcium channel generated reduced the calcium entry into bovine sperm cells, restricting motility and increased survival of these cells. We propose to in the future explore whether the modulation of calcium channels in bovine sperm cells can reduce motility and increase the survival of these cells in experimental conditions, to reduce the mortality of the sample and improve laboratory manipulation.