[The effect of age on the in vitro response to insulin in the rat. I. Glucose metabolism on the diaphragm (author's transl)].

No modification in basal radioglucose metabolism by isolated rat diaphragm could be seen with senescence. Insulin increased the production of 14CO2 only in growing animals. On the opposite, incorporation of radioglucose into glycogen is enhanced in the different age groups; nevertheless, the response in 3-month-old animals was lower than in 6-week-old ones. No significant difference has been detected between the adult and the old rats. Therefore, it is concluded that a diminution of insulin sensitivity appeared during the period of transition between growing up and maturity without any further modification during old age.