32 In this nonrandomized study, 56 men who had a bilateral nerve-sparing operation
began treatment with 125 µg PGE1 3 times a week within 4 weeks of surgery; another 35 men served as an observational control group. Treatment was continued for approximately 6 months, with the dose of PGE1 increased to 250 µg after 6 weeks. In the PGE1 group, 38 of 56 men (68%) Inhibitors,research,lifescience,medical continued treatment for the entire 6 months. At 6 months, 28 of 38 men (74%) resumed sexual activity; 15 (39%) had natural erections sufficient for vaginal penetration without treatment, and 13 (34%) used PGE1 as an erectile aid when having intercourse. In the observation group, 13 out of 35 men (37%) resumed sexual activity, 4 (11%) had natural erections sufficient for vaginal penetration, Inhibitors,research,lifescience,medical and 9 (25%) used adjuvant treatments. This encouraging but nonrandomized small study suggests that postoperative
transurethral PGE1 is well tolerated and may be beneficial in penile rehabilitation in the ED that accompanies RP. The click here ability of PGE1 to increase smooth muscle relaxation and blood supply, even in the presence of local nerve trauma, suggests that the drug may rehabilitate nerves and blood vessels that are Inhibitors,research,lifescience,medical damaged during surgery. One possible mechanism of nerve rehabilitation is through cyclic adenosine monophosphate (cAMP), which is reported to play a role in regeneration in both the peripheral and central nervous systems.33,34 In an in vitro model of axotomy using adult retinal ganglion cell axons, increasing cAMP promoted growth cone regeneration under conditions that normally would result in low regenerative potential.35 Jiang and associates36 demonstrated that endogenous levels Inhibitors,research,lifescience,medical of cAMP are higher Inhibitors,research,lifescience,medical in young neurons, which are able to regenerate after injury, as compared to older neurons, which lose the ability to regenerate. Kogawa and colleagues37 reported on nerve regeneration in dorsal root
ganglia (DRG) of diabetic rats. Prior to nerve crush injury there were no apoptosis-positive DRG neurons observed; subsequent to axonal injury, apoptosis-positive neurons were seen in diabetic but not in until nondiabetic animals or in rats treated with a PGE1 analog. The regeneration distance at day 7 after injury was shorter in diabetic rats than in animals in the other groups. The cAMP content of DRG on day 7 was higher than that at day 0 in nondiabetic and PGE1-treated animals, whereas it was not increased after 7 days in diabetic rats. The results suggest that PGE1 is able to rescue DRG neurons from apoptosis and that it improves axonal regeneration in diabetic rats. The beneficial effect of PGE1 on corporal oxygenation was demonstrated by Padmanaban and colleagues.38 In 101 patients with ED, the administration of PGE1 intraurethrally or intracorporally resulted in a 37% to 57% increase in corporal oxygen saturation (StO2).