Studies of the Carbohydrate Metabolism of Mammary Gland Tissue in Vitro. I. Production and Utilization of Various Carbohydrate Substances

Abstract

Summary 1. It has been possible to increase the concentration of gycogen in perfused mammary gland tissue to a level comparable to that of normal intact mammary glands. This was accomplished by the perfusion of excised mammary glands with high concentrations of blood glucose. 2. It has been possible to convert the glycogen formed during perfusion to lactose by means of incubation of the perfused tissues. This does not in any way prove that this is the path of lactose formation in mammary glands, but it appears to be a possible mode of metabolism by which several compounds could be converted to lactose. 3. Glycogen could not be increased in incubating tissue breis from glucose, lactic acid, pyruvic acid and citric acid individually, and in combinations of these, as well as in the presence of added glycogen. 4. Lactose was formed during incubation of mammary tissue slices with glucose, glucose and lactic acid, maltose, and glycogen. 5. Lactic acid was formed in incubating tissue alone, as well as from added glucose, maltose, glycogen, pyruvic acid, and citric acid.