Insulin and isoproterenol induce phosphorylation of the particulate cyclic GMP-inhibited, low Km cyclic AMP phosphodiesterase (cGI PDE) in 3T3-L1 adipocytes.

The cGI PDE in particulate fractions of differentiated adipocytes (but not control 3T3-L1 fibroblasts) was cross-reactive with a polyclonal antibody raised against the bovine adipose cGI PDE. The 3T3-L1 adipocyte cGI PDE is a 135 kDa protein which is phosphorylated in 32P-labeled cells in response to beta-agonist or insulin. These results indicate that the 3T3-L1 cGI PDE is similar in structure and hormonal regulation to the analogous enzyme in the rat adipocyte.