Functional inhibition of erectile process in rats by indomethacin.

OBJECTIVES: Despite the important role played by prostaglandins in the control of erection, the potential contribution of non-steroidal anti-inflammatory drugs in erectile dysfunction in experimental animals has not been investigated. We examined the effect of the selective COX-2 inhibitor, celexocib, and the non-selective COX-inhibitors, indomethacin and diclofenac on erectile process in vivo.
METHODS: Erectile responses to electrical stimulation of the cavernous nerve in anesthetized male rats were recorded after single and repeated administration and intracavernosal pressure/mean arterial pressure (ICP/MAP) was calculated. The effect on blood pressure during erection and total plasma nitrite/nitrate level was also investigated.
RESULTS: Single-dose administration of indomethacin significantly reduced erectile responses to electrical stimulation at all frequencies tested; 15 mg/kg further reduced ICP/MAP to 0.016 ± 0.005 compared to 0.064 ± 0.012 and 0.104 ± 0.035 for indomethacin (5 mg/kg) and control, respectively at 0.5 Hz. Longer-term treatment with indomethacin completely abolished erectile responses at low frequencies and significantly reduced ICP/MAP at higher frequencies, accompanied by significant reduction in total plasma nitrite/nitrate level. Diclofenac reduced erectile responses only at low frequencies in contrast to celexocib that failed to negatively affect erectile responses.
CONCLUSION: Indomethacin, and to a lower extent diclofenac, may adversely affect erectile responses in rats.