Effects of Intratracheal Administration of Bleomycin on Prostaglandins and Thromboxane-B₂ and Collagen Levels of the Lung in Hamsters

Abstract

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-PGF_1α (stable metabolite of PGI₂ TxB₂ (stable metabolite of TXA₂), PFG_2α, 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.