Biochemical Changes in Tissues during Infectious Illness: Metabolic Consequences of Interactions between Infectious Illness and Forced Exercise

摘要

Infectious illness, forced exercise and energy source were studied in one, two or three-way interactions. Both weanling male rats and day-old cockerel chicks were used to observe species differences. Challenges with infectious illness, e.g., S. typhimurium for rats and avian tuberculosis for chicks, were considered low level. Maximum forced exercise (running wheels) period was a 2-hour session at 10 rpm. Nutritional sub-plots were included which permitted comparisons of glucose, fructose or sucrose as the major source of dietary energy. Statistical analyses of the data indicated that infection and forced exercise effects were specific with little interaction. Not only were liver parameters affected but also protein synthesis in the heart; these effects were more pronounced when fructose was fed. Liver glucose and glycogen levels were slightly lower in control and infected rats forced to run 2 hours than in rats allowed to exercise voluntarily for the same length of time. Of the biochemical data observed, liver glycogen appeared to have the most immediate response to infection and/or exercise. A reduction in hepatic glycogen generally correlated with a decrease in triglycerides in fat pads and an increase in blood transport. An overview of the data on sucrose vs fructose as the major source of dietary energy during infectious illness and forced exercise tends to indict the nutritional worth of fructose. This is of military importance since fructose now makes up a significant part of the human diet.