PI3K activity in MCK-hLAR mice. Phosphotyrosine- (a),
IRS-1- (b), or IRS-2-associated (c) PI3K
activity in muscle of male mice, phosphotyrosine-associated PI3K
activity in muscle of female mice (d), and
IRS-1-associated PI3K activity in liver of female mice
(e). Mice were fasted for 16–18 h, injected i.v. with
saline or insulin (10 units/kg), and killed 3 min postinjection. PI3K
activity was measured in phosphotyrosine, IRS-1, or IRS-2
immunoprecipitates of hind-limb muscles or liver as described in
Materials and Methods. Results are mean ± SEM for
three to five mice per group. *, difference from nontransgenic
insulin-stimulated is P < 0.05. Similar results
were seen in male and female mice.