Some features of age-related insulin responsiveness in rat hepatocytes.

Different features of insulin sensitivity have been considered, in rat hepatocytes, with respect to their age-dependence. In particular, plasma membrane-located responses such as (Na/K)-ATPase and Na-dependent aminoacid transport were studied together with cytoplasmic responses such as the insulin-stimulated tyrosine aminotransferase. It appears, as far as the insulin sensitivity is concerned, that the age of the animal does not affect plasma membrane-bound events whereas plasma membrane-mediated intracellular responses are definitely impaired. Insulin binding to intact hepatocytes does not seem to be age-dependent.