Fig. 4. Influence of nitrous oxide on Src kinase phosphorylation (two phosphorylation sites). The phosphorylation state of Src kinase (tyrosine 416 [ A ] and tyrosine 527 [ B ]) in control and nitrous oxide–treated (N2O-PC) hearts (each n = 4) is demonstrated. Upper panel shows respectively phosphorylated form of Src (pSrc); middle panel shows actin distribution. The histogram presents densitometric evaluation as average light intensity (AVI). Data demonstrate ratio of phosphorylated Src versus actin (means ± SD). Equal loading of protein on the gel was confirmed by Coomassie blue staining of the gel (respective lower panel ).