Theophylline inhibition of BCG-induced pulmonary inflammatory responses

The present study was performed to evaluate the effect(s) of theophylline onBCG-induced pulmonary inflammatory responses in an experimental rat model system.Five groups of six animals each received the following: group 1:theophylline-treated, BCG-challenged, and sacrificed three days later; group 2:saline-treated, BCG-challenged, and sacrificed three days later; group 3:theophylline-treated, BCG-challenged, and sacrificed five days later; group 4:saline-treated, BCG-challenged, and sacrificed five days later; and group 5: notreatment and no BCG-challenge ("absolute controls"). Quantitative recovery ofbronchoalveolar lavage (BAL) cells was performed and compared withhistopathologic changes in lung specimens from each animal in all five groups. Nosignificant differences in quantitative BAL cellular recovery were observed intheophylline-treated animals from saline-treated controls. There was asignificant reduction in BAL cell number in saline-treated animals sacrificedfive days after BCG-challenge (group 4) from that seen in saline-treated animals sacrificed three days after BCG-challenge (group 2). The most striking finding, however, was a marked diminution in granuloma formation induced by theophylline five days after BCG challenge (group 3). These findings suggest an antiinflammatory effect of theophylline