Lipolysis and cyclic-3', 5'-AMP content in rat adipose tissue at different age.

The content of cAMP, the release of glycerol and nonesterified fatty acids (NEFA) of adipose tissue with and without the stimulation by ACTH and norepinephrine were determined in young and old rats. After the lipid mobilizing hormones lowered concentration of cAMP and impaired stimulation of lipolytic activity were found in old rats. Furthermore, less stimulation of glycerol and NEFA release by cAMP was observed in these animals. These results suggested that in old animals a lower lipolytic activity per tissue and lipid mass is available in intact and hormone stimulated fat tissue and therefore the accumulation of lipids in fat depots is facilitated.