Effect of chronic lithium administration on endothelium-dependent relaxation of rat corpus cavernosum: the role of nitric oxide and cyclooxygenase pathways
Article first published online: 11 OCT 2006
Volume 99, Issue 1, pages 177–182, January 2007
How to Cite
Sadeghipour, H., Ghasemi, M., Nobakht, M., Ebrahimi, F. and Dehpour, A. R. (2007), Effect of chronic lithium administration on endothelium-dependent relaxation of rat corpus cavernosum: the role of nitric oxide and cyclooxygenase pathways. BJU International, 99: 177–182. doi: 10.1111/j.1464-410X.2006.06530.x
- Issue published online: 7 NOV 2006
- Article first published online: 11 OCT 2006
- Accepted for publication 31 July 2006
- erectile dysfunction;
- corpus cavernosum;
- nitric oxide;
To verify the effect of chronic lithium administration on the endothelium-dependent relaxation of rat corpus cavernosum, as lithium is a major drug for treating bipolar disorder and some studies showed that lithium might cause erectile dysfunction in such patients, by a mechanism as yet unknown.
MATERIALS AND METHODS
LiCl (600 mg/L) was dissolved in drinking water and Sprague–Dawley rats received the solution for 30 days; control rats received tap water. After 30 days corporeal strips were prepared from both groups, mounted under tension in oxygenated organ baths, and pre-contracted with phenylephrine (7.5 µm). After equilibration, the strips were relaxed by acetylcholine (10 nm to 1 mm) in the presence or absence of indomethacin (a cyclooxygenase inhibitor; 20 µm). Furthermore, the relaxant responses to sodium nitroprusside (1 nm to 1 mm), a nitric oxide (NO) donor, were investigated in both groups. NADPH-diaphorase histochemistry was used to identify NO synthase within cavernosal tissue strips of both groups.
The acetylcholine-dependent relaxation was significantly lower in lithium-treated rats than in controls. Although indomethacin decreased significantly the relaxant responses to acetylcholine in controls, it increased the relaxant responses in lithium-treated rats. NADPH-diaphorase staining was greater in the chronic lithium-treated than in control preparations. Sodium nitroprusside produced similar relaxation in both groups.
Chronic lithium administration can impair the endothelium-dependent relaxation of rat corpus cavernosum; NO availability might decrease after lithium administration and the cyclooxygenase pathways might have a role in this effect.