Ultrastructural damage in lung tissues in rats treated with doxorubicin and paclitaxel

The aim of this study was to determine the ultrastructural effects of doxorubicin (Adriblastina; Pharmacia and Upjohn, Milan, Italy), paclitaxel (Taxol; BMS, Princeton, NJ), Cremophor EL (a diluent of paclitaxel) and doxorubicin/paclitaxel combinations on normal lung tissues.

In the experimental protocol, 50 Wistar albino rats were used, divided into five different groups: the control group (n=10), the doxorubicin group (1 mg/kg) (n=10), the paclitaxel group (2 mg/kg) (n=10), the Cremophor EL group (150 mg/kg) (n=10) and the paclitaxel/doxorubicin group (2 mg/kg+ 1 mg/kg) (n=10). The drugs were administered weekly to rats via intraperitoneal injections for 14 weeks. After 3 weeks of observation, the rats were killed with thiopental sodium (30 mg/kg) and their left median lung tissues were removed and examined with a Carl Zeiss EM 900 transmission electron microscope.

Our experiments showed doxorubicin to cause an increase in collagen fibre content of the alveolar wall, and paclitaxel to cause degenerations in cellular organelles. In the group in which the two agents were administered together, both effects were observed, although the effects of paclitaxel were seen to be dominant. Ultrastructural appearance was similar in the Cremophor EL group compared to the control group.

It was detected that doxorubicin and paclitaxel caused ultrastructural degenerations in normal lung tissues and Cremophor EL seemed to be unaccountable for these degenerations.