Antinociceptive effect of PTH2R block in the tail-flick and hot-plate tests. Tail-flick (A, C and E) or hot-plate (B, D and F) tests were performed following icv (A, B, C and D) or intrathecal (E and F) administration of the indicated amounts of the PTH2R antagonist HYWH or 500 pmol PTH2R agonist TIP39. The response latency significantly increased in both tests following icv administration of HYWH (500 pmol) and decreased following TIP39 administration. Intrathecally administered HYWH significantly increased the response latency only at a higher dose (2.5 nmol). *P<0.05, ***P<0.001.