Recently,
prostaglandins have been shown to be effective agents for the treatment of
cyclophosphamide-induced
hemorrhagic cystitis. Among the
prostaglandins studied is
carboprost tromethamine, a PGF2a analog. To determine the effectiveness of
carboprost tromethamine therapy on the urothelium, we induced
hemorrhagic cystitis in 81 rats. These were divided into two treatment arms. One arm was treated prophylactically at the time of
cyclophosphamide injection, and the other started treatment only after
hemorrhagic cystitis was established. Animals were divided equally into groups receiving 0, 0.4, 0.8, and 1.6 mg.%
carboprost tromethamine in 0.9%
normal saline by continuous bladder irrigation. All bladders were examined grossly for
edema and
hemorrhage, then histologically for mucosal ulceration, congestion, and perivascular
hemorrhage. Results from the prophylactic arm, as compared to those for controls, revealed that all groups except those treated only with 0.9%
normal saline had a lower incidence of
hemorrhagic cystitis (p less than 0.05). In the established
hemorrhagic cystitis arm, the group treated with 1.6 mg.%
carboprost tromethamine showed the best response (p less than 0.05), whereas the group treated with 0.9%
normal saline showed the poorest response. This study reveals that
hemorrhagic cystitis in the rat model may be prevented by prophylactic continuous bladder irrigation with
carboprost tromethamine, whereas established
hemorrhagic cystitis may be treated effectively with
intravesical instillation of
carboprost tromethamine. Although the mechanism of action of this
prostaglandin on the urothelium is unknown, it appears grossly and histologically to decrease ulceration, perivascular
hemorrhage, and congestion in the mucosa and submucosa.