Metabolic Responses to Swimming Exercise in the Infected Rat

摘要

Bacterial infections cause a reduction in physical performance capacity. Studies were performed to determine if alterations in fuel reserves or energy substrate utilization might explain these decrements in performance. Untrained rats found adaptable to the swim task were divided into sedentary and exercised groups. These groups were subdivided into fed, fasted and fasted-infected rats. Fed rats were used for baseline values. Fasted rats were studied at 24, 48 and 72 h after removal of food and inoculation with heat-killed Streptococcus pneumoniae. Fasted-infected rats were injected with an equal number of viable bacteria and studied at the same time intervals. All exercised groups were studied immediately following a 2-h swim or swim-induced exhaustion. In the absence of infection, fed- and fasted-sedentary and exercise parameters were compatible with previously reported values. Infection caused depletion of glycogen stores, hyperglycemia, hypolipidemia, inhibition of ketone body accumulation and increased circulating plasma insulin and glucagon despite concurrent fasting. Exercise superimposed on infection and associated anorexia amplified these aberrations. Superimposed exercise did not alter the direction of infection-induced changes, but did alter the magnitude of metabolic responses. It was not possible, however, to relate alterations in fuel metabolism directly to reduction in performance. (Author)