[Age and features of insulin reception by the plasma membranes of liver cells]

The specific binding of 125I-insulin by liver cell plasmatic membranes of rats aged 5-6 mos. and 24-26 mos. was studied. A decrease in hormone binding with the receptors of old animals as compared to young ones in the presence of similar concentration of immunoreactive insulin in the blood was established. A graphical analysis of the data after Scatchard showed that an age-related decrease in 125I-insulin binding with rat liver cell plasmatic membranes resulted from the loss of binding sites in old rats as compared to young animals. The affinity of insulin receptors to the hormone did not change with age.