Bladder contributes to eicosanoids excreted in urine.

The excretion of eicosanoids was examined in urine collected from the bladder or the ureter in normal rats. We found that the excretion of thromboxane B2 (the stable metabolite of thromboxane A2), prostaglandin E2, and 6-ketoprostaglandin F1 alpha was significantly greater in urine collected from the bladder than in urine collected from the ureter. This suggests that the bladder contributes significantly to the amount of eicosanoids present in the urine.