Fig. 1. The chemical structure of Vactosertib and study design. (A) Structures of Vactosertib. (B) Study protocol. Rats received injections consist of 100 µL of human fibrin and 100 µL thrombin solutions on days 0 and 5, respectively into the tunica albuginea to induced Peyronie's disease (PD)-like plaques. Vactosertib (10 mg/kg) or vehicle (simulated gastric fluid) was given orally five times a week for 2 weeks. On day 30, erectile function was assessed, and erectile tissue was harvested for histological examination.