Motility, viability, and calcium in the sperm cells

Sperm cells are complicated in vitro models. Their viability is limited, and physiology is complex. The study of their properties is of great application in the animal production as viable and functional gametes are essential. It has been shown that the decrease of sperm cell viability parallels an increase of the reactive oxygen species (ROS). Reactive oxygen species is secondary to normal metabolic processes of the cell-like flagellar movement. There is evidence of strategies that reduce ROS levels by using exogenous or endogenous antioxidants with the intention that seminal plasma protects the sperm cells and increases viability. Perhaps viability can increase by reducing that flagellar movement which is regulated by calcium. The phenomenon has not been fully characterized, but it is established that in certain mammalian models, the entrance of calcium via specific channels such as CATsper or voltage-dependent channels, signals flagellar movement. Previous reports have indicated that a change in the concentration of calcium or if the temperature is altered, the function of mammal sperm cells is reduced or blocked and viability prolonged. Fish sperm can remain immobile for several weeks but when activated the number of mobile and viable sperm is reduced at a faster rate. However, if the cells are not mobilized the semen can be preserved for longer periods. As presented in this paper, this supports the notion that by modulating calcium channels to reduce motility the viability of these cells can increase.