Fig. 7. The effects of valproic acid treatment on the period of Period1-bioluminescence rhythms and the phosphorylation level of JNK in rat-1 fibroblasts.
(A) Rat-1 fibroblasts were synchronized and treated with 1 mM valproic acid. Period was significantly shortened in the presence of valproic acid. Values are means±S.E.M. In each graph, a number shown in a column indicates sample size. * P<0.05. Student’s t-test. (B) Rat-1 fibroblasts were cultured and treated for 12 h with either 30 μM SP600125 or 1 mM valproic acid. SP600125 (SP) did not significantly affect the phosphorylation levels of p46 kDa and p54 kDa, while valproic acid (VA) hyper-phosphorylated both isoforms. Total JNK levels were not affected by SP or VA treatment. Values are means±S.E.M. n=3–4 For each treatment. ** P<0.005; *** P<0.0005; ns, not significant.