Abstract
Aerobic incubation of rat diaphragms in Warburg flasks (Krebs-Ringer PO4 without Ca, pH 7.3-7.4, with glucose added to initial concn. of 300 mg./ 100 ml.) after a preliminary 30_min. equilibration period caused disappearance of glucose from the medium, glycogen formation in the diaphragm and lactate formation. Adrenalectomy and hypophysectomy did not significantly alter these activities. The addition of 0.5 or 2.5 mg. of cortisone acetate microcrystals inhibited the glucose disappearance markedly and somewhat reduced the QO2. Lactate formation and glycogen deposition were unchanged. The effect of 2.5 mg. of cortisone/flask was greater in diaphragms from hypophysectomized and adrenalectomized rats than from those of normal rats. With 0.5 mg. cortisone/flask, no increased effect occurred. The doses used are extremely large, and even the smaller dose was not entirely dissolved in the medium. Control soln. consisted of 0.9% NaCl 1.5% benzyl alcohol, 0.4% tween 80 and 0.5% sodium-carboxymethyl-cellulose.