Protein synthesis increases with meal size and correlates with postprandial metabolic rate and organ mass in Burmese pythons (Python bivittatus)

Abstract

Feeding is associated with large increases in metabolism (Specific Dynamic Action of food; SDA response) and rapid growth of many visceral organs in the Burmese python (Python bivittatus). Both magnitude and duration of the SDA response increases with meal size, which has been attributed to the extra digestive workload with increasing meal size. However, recent data shows a large increase in postprandial protein synthesis, which aligns with the high growth-efficiency of pythons, suggesting that postprandial protein synthesis is involved in tissue remodelling and plays a pivotal role in the SDA response. In this study, we investigated whether meal size correlates with protein synthesis, oxygen consumption, organ mass, and plasma amino acid concentrations in Burmese pythons. The results showed that both oxygen consumption, and protein synthesis increased with meal size. Comparison of models revealed that both meal size and protein synthesis independently drive the variation in organ mass, this supports that protein synthesis drives the organ growth seen during the postprandial period. Although slightly declined at the largest meal size, the rise in protein synthesis likely involves both substrate availability and hormonal regulation. These findings reinforce the concept that protein synthesis is a key driver of the SDA response and the postprandial organ flexibility of Burmese pythons.