Incorporation of C14-histidine into protein of isolated diaphragms: interaction of fasting, glucose and insulin

Abstract

The interaction of fasting, glucose availability and insulin on protein synthesis was investigated using the isolated rat diaphragm incubated in vitro with histidine-2-C¹⁴. Prior fasting of the diaphragm donor leads to a decrease in the rate of incorporation of histidine-2-C¹⁴ into muscle protein; the decrease after a 12- or 24-hour fast is small, that after a 48-hour fast is marked. A definite influence of glucose concentration can be demonstrated only when the donor rat has been fasted 48 hours; and only in diaphragms from such fasted animals is the insulin anabolic effect dependent on the availability of extracellular glucose.