['To investigate the effect of p38 mitogen-activated protein kinase (p38MAPK) on the expression of COX-2 and caspase-3 in the substania nigra (SN) of mice with MPTP-induced Parkinson disease (PD).', 'C57BL/CN mice were treated with MPTP to prepare a subacute PD model, and their behavioral changes following the treatment were observed. Immunohistochemistry and Western blotting were performed to detect the expression of tyrosine hydroxylase (TH), COX-2 and phosphorylation of P38MAPK in the SN and their changes following treatment with SB203580, a specific inhibitor of P38MAPK.', 'The 7-day model group showed typical symptoms of PD with decrements of TH-positive neurons and TH protein level in the SN of the midbrain by about 65% and 75%, respectively (P<0.01). In the 3-day model group, the COX-2-, caspase-3- and phosphorylated P38MAPK-immunoreactive cells and their protein levels in the SN increased markedly with obvious loss of TH-positive neurons. Administration of SB203580 obviously lessened the above changes (P<0.01).'] Does [ P38MAPK pathway regulate COX-2 and caspase-3 expression in a mouse model of Parkinson disease ]?