Eating increases oxidative damage in a reptile

Area of Science:

• Physiology
• Zoology
• Biochemistry

Background:

• Digestion provides nutrients and energy but incurs physiological costs.
• While energy expenditure is well-studied, other physiological costs of eating are less explored.
• Oxidative stress, an imbalance between pro-oxidants and antioxidants, is a potential cost of metabolic processes.

Purpose of the Study:

• To investigate the impact of eating on systemic pro-oxidant (reactive oxygen metabolite, ROM) levels and antioxidant capacity.
• To quantify the oxidative cost of meal processing in corn snakes (Pantherophis guttatus).

Main Methods:

• Plasma samples were collected from corn snakes during absorptive (post-meal) and non-absorptive (baseline) states.
• Systemic reactive oxygen metabolite (ROM) levels and antioxidant capacity were measured.
• Data were analyzed controlling for circulating nutrient levels.

Main Results:

• A minimal increase (4%) in antioxidant capacity was observed during the absorptive state compared to baseline.
• A substantial increase (nearly 155%) in ROM levels was detected during the absorptive state, even after controlling for nutrient levels.
• The oxidative cost of eating was found to be significantly higher than costs associated with long-distance flight or immune responses in other species.

Conclusions:

• Eating incurs a significant oxidative cost in corn snakes, characterized by a marked increase in ROMs.
• This finding underscores the importance of investigating non-energetic physiological costs of meal processing.
• Further research is needed to elucidate the mechanisms driving eating-induced ROM increases and their taxonomic prevalence.