Figure 8 - Mitogen-activated protein (MAP) kinases mediate PKC-dependent LES basal tone.

MAPK kinase (MEK) inhibitors prevent phosphorylation and activation of the MAP kinases ERK1 and ERK2. The MEK inhibitor PD98059 or the p38 MAP kinase inhibitor SB203580, when used alone, produced concentration-dependent reductions in LES tone [p = .001, analysis of variance (ANOVA)]. LES tone was further reduced when PD98059 and SB203580 were used in combination (p = .001, ANOVA), suggesting that PKC-dependent tone is mediated by ERK1/2 and p38 MAP kinases. Values are means + SE of three animals. (Source: Cao et al.,⁴⁵ with permission from the American Physiological Society.)