Effect of CO on cdk activity and cdk2 protein in vascular SMCs.

Cells were treated with serum (5%) and SnPP (20 μM) for 24 hours in the presence and absence of CO (200 ppm) and cyclin A–associated kinase and cdk2 activity (A) determined as described in “Materials and methods.” The cdk2 protein levels (B) were monitored by Western blotting. Similar findings were observed in 3 separate experiments.