Effects of intratracheal administration of bleomycin on prostaglandins and thromboxane-B2 and collagen levels of the lung in hamsters.

The effects of intratracheal administration of one unit of bleomycin on the lung levels of different prostaglandins (PGs), thromboxane B2 (TxB2), and total collagen were investigated in hamsters in two separate sets of this study. Averaging the values from two sets, the lung levels of 6-keto-PGF1 alpha (stable metabolite of PGI2), TxB2 (stable metabolite of TXA2), PFG2 alpha, and PGE in bleomycin-treated animals were increased by 11-, 7.5-, 7-, and 3-fold over the saline control at 14 days post treatment, respectively. The total lung collagen content in bleomycin-treated animals was significantly increased to 180% of the control during the same period. A number of possibilities for a marked variation in the levels of rise for different PGs and TxB2 and their significance in bleomycin-induced lung fibrosis have been discussed. It was concluded from the findings of the present study that there is a relationship between the lung levels of various metabolites of arachidonic acid cascade and bleomicin-induced increases in the synthesis and accumulation of lung collagen. The nature of this relationship, however, remains to be elucidated.