Muscle Glycogen in Man Determined in Needle Biopsy Specimens Method and normal values

A method has been devised for determination of the glycogen content of human skeletal muscle, obtained with a needle biopsy technique.The method involves homogenization of the muscle specimens. The protein is precipitated with trichloroacetic acid. After precipitation of the glycogen with alcohol from the supernatant, it is hydrolyzed with sulphuric acid, and then determined as glucose with the orthotoluidine method.In 96 per cent of healthy subjects, the glycogen content of the quadriceps femoris muscle ranges from 0.95 to 2.0 g/100 g wet muscle (mean 1.39 g). The standard error of the method is 0.05 g/100 g, representing 3.5 per cent of the mean value. The glycogen content of the deltoid muscle (mean 0.98 g/100 g wet muscle) is significantly lower than that of the quadriceps femoris.A study was also made of the diurnal fluctuations in the muscle glycogen, both under normal conditions and during brief fasting. These fluctuations are found to be small and not uniform.