Lactate and Pyruvate Are Major Sources of Energy for Stallion Sperm with Dose Effects on Mitochondrial Function, Motility, and ROS Production.

The research article shows that stallion sperm uses lactate and pyruvate as primary energy sources, these substances also influence the speed and motility of sperm. In addition, the presence of pyruvate and lactate in the media allows for optimal mitochondrial function. Interestingly, the researchers found that the addition of glucose for short-term storage is not necessary and could potentially reduce mitochondrial functionality.

Research Purpose

• The main purpose of the research was to identify the key substances needed for optimal mitochondrial function in sperm. The researchers used the substances included in the BWW media for their experiments.
• The researchers hypothesized that the mitochondrial substrates, pyruvate and lactate would be more supportive of sperm motility than the glycolytic substrate, glucose.

Research Methodology

• The researchers incubated sperm in modified BWW media with varying concentrations of lactate, pyruvate, and glucose.
• The impact of the media and duration of incubation on sperm motility, ROS production, and oxygen consumption were determined using a statistical model called linear mixed-effects.
• The researchers used repeated ejaculations from four different stallions in three separate experiments to examine the effects of substrate availability and concentration on sperm motility and mitochondrial function. They also studied the relationship between oxygen consumption and cellular ROS production.

Key Findings

• The findings of the study indicated that lactate and pyruvate are major sources of energy for sperm motility and velocity. Additionally, there was a dose-dependent response observed, i.e., the rate of response is proportional to the amount of these substances.
• In media with lactate and pyruvate, the sperm operated at a very high level of their bioenergetic capacity because of a high rate of energy metabolism, indicating that these substances are ideal for maximal mitochondrial function.
• Interestingly, the researchers found that adding glucose to the media is unnecessary for short-term sperm storage and may reduce mitochondrial function, contradicting their initial hypothesis.
• The research also found that ROS production can result not only from mitochondrial dysfunction but also from intense mitochondrial activity, further laying ground for the importance of pyruvate and lactate in the energy production process.