Residual Glycogen Research Articles

Effects of anabolic steroids on carbohydrate metabolism. I. Experimental study with the use of glycine-1-14C.

1) The effects of castration for 25days and norandrostenolone phenylpropionate (NAPP) administration to these castrated animals on the glycogen contents of the liver and rectus femoral muscle were studied. Following the castration remarkable decrease of tissue glycogen was found, which was somewhat prevented by the treatment with NAPP. The ratio of TCA extractable glycogen to total one was almost invariable in every case.2) One mg daily of TP, NAPP, cortisone and cortisone plus TP respectively was injected to young male rats for 3days.The administration of TP and NAPP showed no influence upon the liver glycogen content but in the muscle a considerable increase of glycogen was observed, which was mostly due to an increase of TCA extractable one.The administration of TP in addition to cortisone had little influence upon tissue glycogen already increased markedly by cortisone.3) After the injection of glycine-14C higher 14C-specific activity of tissue glycogen was noted in the animals treated previously with NAPP than in the castrated. The incorporation of 14C due to 14C-glycine administration was observed in liver glycogen first and 3-6 hrs. later in muscle glycogen.Higher radioactivity was found in the residual glycogen than in the TCA extractable one in every case.Therefore it might be suggested that anabolic steroids such as NAPP may have the action to accelerate gluconeogenesis from glycine and other amino acids.Some mechanisms of androgens on carbohydrate metabolism, especially on the gluconeogenesis from amino acids were discussed.

Glycogen metabolism.

Glycogen metabolism.

Effects of cardiac work on glycogen fractions of the heart.

Trichloroacetic acid soluble (TCA) glycogen and residual glycogen were determined in the left ventricle and interventricular septum of hearts of unfasted male albino rats. Left ventricular hypertrophy and an elevation of blood pressure were produced in rats by coarctation of the abdominal aorta for a period of 5 days. No change in concentration of either cardiac glycogen fraction was found at the end of the 5-day coarctation period. Coarctation of the abdominal aorta for 1 hour failed to alter the glycogen fractions of the left ventricle, whereas complete ligation of the aorta for the same time interval promoted the deposition of TCA glycogen. In rats subjected to 5, 15 and 60 minutes of swimming, left ventricular glycogen was significantly depleted. Residual glycogen resynthesis was complete after 1 hour of rest from 15 minutes of exercise, and the TCA fraction was significantly increased at this time. Method of sacrifice influenced the concentration of the cardiac glycogen fractions. The above experimental procedures predominantly affected the TCA fraction of cardiac glycogen.

Abnormally low ultimate pH in pig muscle.

THE pH attained when the process of post-mortem glycolysis has ceased—the ultimate pH1—is influenced by the type of muscle considered, the species in which it occurs and the physiological condition of the animal from which it is derived. In the longissimus dorsi (1. dorsi) muscles of horses2, oxen3 and pigs4, the glycogen reserves of which have not been depleted by such stresses as pre-slaughter exercise, starvation or excitement, an ultimate pH. of about 5.5 is characteristic. At this pH. the enzymes which effect glycolysis are assumed to be inactivated, and residual glycogen may be found. Stress, by depleting glycogen reserves at or before death, is therefore normally associated with values of ultimate pH above 5.5.

Extractable and Residual Glycogen in Tissues of the Rat

Extractable and Residual Glycogen in Tissues of the Rat

Residual glycogen at high ultimate pH in horse muscle

Residual glycogen at high ultimate pH in horse muscle