The effect of insulin on the liver cells of newborn rats. An electron microscopic study

The liver of newborn rats contains neither glycogen nor lipid droplets. These latter, sometimes in fusion, still could be found in the cytoplasm and the nucleus as well, following a five-minute action of insulin at a dose of 0.2 IU/animal. The lipid droplets were in close relationship with the mitochondria. This time the glycogen, either in fields or rosettes, was missing. Thirty minutes after treatment the fields of glycogen could be well seen. The experiments demonstrated an exclusive sequence of events starting with the receptor and its signal insulin on neonatal liver cells and resulting in a morphological picture (involving first lipid droplets, then glycogen), similar to that of the adult liver cells.