The resetting of the circadian rhythm by Prostaglandin J2 is distinctly phase-dependent.

The circadian rhythm can be reset by a variety of substances. Prostaglandin J(2) (PGJ(2)) is one such substance and resets the circadian rhythm in fibroblasts. In our current study, we examined the phase-dependent phase shift following PGJ(2) treatment using a real-time luciferase luminescence monitoring system. In the phase response curves, we observed 12h differences in the times of peaks in comparison with the same analysis for forskolin. Quantification of clock gene mRNAs following PGJ(2) administration additionally revealed a rapid decrease in the Per1, Rev-erbAalpha and Dbp levels. Our current findings thus suggest that PGJ(2) resets the peripheral circadian clock via a mechanism that is distinct from that used by forskolin (FK).