Average MPO activity in the various experimental groups in the continued and discontinued injection subgroups (readings represent average of day 3, 7, 14, 28, 42, 56, and 70 in each group). The increase in the MPO activity in the IA+B subgroup was significantly greater (P < 0.005) compared to all the other subgroups. The IA continued injection subgroup also showed a significant increase (P < 0.005) compared to the control group.