Effects of intracerebroventricularly administered opioid peptide antagonists on tissue glycogen levels in rats after exercise.

Background/aim: Physical exercise is a state of physiological stress that requires adaptation of the organism to physical activity. Glycogen is an important and essential energy source for muscle contraction. Skeletal muscle and liver are two important glycogen stores, and the energy required to maintain exercise in rodents are provided by destruction of this glycogen depot.