What statement best describes the effects of oxidative stress on muscle cells?

• A. It enhances muscle regeneration.
• B. It causes irreversible cell cycle exit.
• C. It leads to increased myoblast proliferation.
• D. It does not affect muscle function.

Answer: (B)

Oxidative stress refers to an imbalance between the production of reactive oxygen species (ROS) and the body’s ability to detoxify these harmful byproducts or repair the resulting damage. In muscle cells, excessive oxidative stress can result in significant cellular damage, including damage to DNA, proteins, and lipids.

Among the options presented, the statement that oxidative stress causes irreversible cell cycle exit is accurate. When muscle cells experience high levels of oxidative stress, the damage can trigger pathways that lead to senescence or apoptosis, effectively removing these damaged cells from the cell cycle. This means that the cells lose their ability to proliferate and regenerate, which has profound implications for muscle repair and function.

The assertion that oxidative stress enhances muscle regeneration or leads to increased myoblast proliferation contradicts the known effects of oxidative damage on cellular health. While some degree of ROS is necessary for signaling pathways involved in muscle repair, excessive oxidative stress is detrimental and stops cells from dividing. Additionally, implying that oxidative stress does not affect muscle function neglects the well-documented negative impact it has on muscle health and performance due to mitochondrial dysfunction and loss of cellular integrity. Therefore, the best description of the effects of oxidative stress on muscle cells is that it leads to irreversible cell cycle exit,