Figure 9

NE and clonidine activate PKCζ in canine mesenteric vein. Phosphorylation of a specific PKCζ peptide substrate (PKCζPS) in vitro by total protein extracts obtained from untreated controls (CT) and tissues incubates for 3 min with 1 μM NE (A) or 1 μM clonidine (B), without or after 60-min preincubation with LY-294002 (10 μM), myristoylated PKCζ peptide inhibitor (PKCζI, 50 μM) or yohimbine (Yoh, 0.1 μM). Phosphorylation of the PKCζ PS (i.e. density of the phospho-PS dots) was quantitated by radiography and densitometry (insets). Phosphorylation of PKCζSP in treated tissues is presented relative to non-treated tissue controls (bar graph, n = 3). *, P < 0.05 versus control; #, P < 0.05 versus veins treated with NE or clonidine.