Figure 4.

Protein tyrosine nitration in smooth muscle from inflamed colon. Membrane extracts were obtained from distal colonic smooth muscle cells from normal (Nor) and inflamed (Inf) mice, and lysates were subject to immunoprecipitation with rabbit anti-nitrotyrosine (NY) (A) or rabbit anti-Ca²⁺ channel (Cav1.2) (B) antibodies and immunoblotted using mouse anti-nitrotyrosine (anti-NY) antibodies. Nitration of Ca²⁺ channels (arrow) was significantly higher in inflamed colon (bottom panel). Equal amount of protein loading was confirmed using anti-GAPDH antibody. *P < 0.05 versus normal (n= 3). Nuclear extracts from distal colons of normal and inflamed mice were subject to immunoblot with either mouse anti-CREB or anti-NY antibodies (C). Protein nitration of CREB was not detected in either normal or inflamed colonic samples. CREB, cyclic AMP response element binding protein.