Abstract
The effects of testosterone and triiodothyronine on cell proliferation and prostacyclin production were investigated using rat aortic smooth muscle cells in culture.
Testosterone at 10-10-10-6M did not affect cell proliferation, but it significantly inhibited prostacyclin production by the cells. Maximal inhibition of prostacyclin production (70%) was observed when cells were treated with a physiological concentration of 10-8M testosterone for 5 consecutive days. On the other hand, T3 at its physiological concentrations had no significant effect on cell proliferation, but it significantly stimulated prostacyclin production by the cells. Maximal stimulation of prostacyclin production was obtained when cells were treated with T3 for 4 consecutive days. The dose-response curve showed a linear relationship between the stimulation of prostacyclin production and T3 concentrations in the range 0.007-10μg/dl. The maximal prostacyclin production by T3 treated cells (at a concentration of 10μg/dl), was 270% compared with control cells. Our results suggest that testosterone and thyroid hormones play an important physiological role on the prostacyclin production by arterial smooth muscle cells.
