TNF and infection: As to the levels in the non-infected paws, atenolol seems to have a reducing effect trend on the TNF-α levels starting day 4 post-infection and throughout the whole experimental period (even when the treatment was stopped); however, atenolol treatment did not reduce the TF low pain thresholds suggesting that this beta blocker can, most probably by down-regulating the TNF-α levels, reduce the peripheral but not the central hyperalgesia.