Aim:

To investigate the effect of icariin on erectile function and the expression of nitric oxide synthase (NOS) isoforms in castrated rats.

Methods:

Thirty-two adult male Wistar rats were randomly divided into one sham-operated group (A) and three castrated groups (B, C and D). One week after surgery, rats were treated with normal saline (groups A and B) or oral icariin (1 mg/[kgday] for group C and 5 mg/[kgday] for group D) for 4 weeks. One week after treatment, the erectile function of the rats was assessed by measuring intracavernosal pressure (ICP) during electrostimulation of the cavernosal nerve. The serum testosterone (ST) levels, the percent of smooth muscle (PSM) in trabecular tissue, and the expression of mRNA and proteins of neuronal nitric oxide synthase (nNOS), inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS) and phosphodiesterase V (PDE5) in corpus cavernosum (CC) were also evaluated.

Results:

ICP, PSM, ST and the expression of nNOS, iNOS, eNOS and PDE5 were significantly decreased in group B compared with those in group A (P < 0.01). However, ICP, PSM and the expression of nNOS and iNOS were increased in groups C and D compared with those in group B (P < 0.05). Changes in ST and the expression of eNOS and PDE5 were not significant (P > 0.05) in groups C and D compared with those in group B.

Conclusion:

Oral treatment with icariin (> 98.6 % purity) for 4 weeks potentially improves erectile function. This effect is correlated with an increase in PSM and the expression of certain NOS in the CC of castrated rats. These results suggest that icariin may have a therapeutic effect on erectile dysfunction.

References

1. Lin CS, Xin ZC, Lin G, Lue TF. Phosphodiesterases as therapeutic targets. Urology 2003; 61: 685–91. | Article | PubMed | ISI |
2. Bischoff E, Schramm M, Straub A, Feurer A, Stasch JP. BAY 41–2272: a stimulator of soluble guanylyl cyclase induces nitric oxide-dependent penile erection in vivo. Urology 2003; 61: 464–7. | Article | PubMed | ISI | ChemPort |
3. Seftel AD, Vaziri ND, Ni Z, Razmjouei K, Fogarty J, Hampel N, et al. Advanced glycation end products in human penis: elevation in diabetic tissue, site of deposition, and possible effect through iNOS or eNOS. Urology 1997; 50: 1016–26. | Article | PubMed | ISI | ChemPort |
4. Podlasek CA, Zelner DJ, Bervig TR, Gonzalez CM, McKenna KE, Mc Vary KT. Characterization and localization of nitric oxide synthase isoforms in the BB/WOR diabetic rat. J Urol 2001; 166: 746–55. | Article | PubMed | ChemPort |
5. Lin CS, Ho HC, Chen KC, Lin G, Nunes L, Lue TF. Intracavernosal injection of vascular endothelial growth factor induces nitric oxide synthase isoform. BJU Int 2002; 89: 955–60. | Article | PubMed | ISI | ChemPort |
6. Bivalacqua TJ, Usta MF, Champion HC, Adams D, Namara DB, Abdel-Mageed AB, et al. Gene transfer of endothelial nitric oxide synthase partially restores nitric oxide synthesis and erectile function in streptozotocin diabetic rats. J Urol 2003; 169: 1911–7. | Article | PubMed | ISI | ChemPort |
7. Hung A, Vernet D, Xie Y, Rajavashisth T, Rodriguez JA, Rajfer J, et al. Expression of inducible nitric oxide synthase in smooth muscle cells from rat penile corpora cavernosa. J Androl 1995; 16: 469–81. | PubMed | ChemPort |
8. Xin ZC, Kim EK, Tian ZJ, Lin GT, Guo YL. Icariin on relaxation effect of corpus cavernosum smooth muscle. Chin Sci Bull 2001; 46: 1186–90. | Article | ChemPort |
9. Tian L, Xin ZC, Liu WJ, Yuan YM, Liu G, Chen L, et al. Effects of icariin on the erectile function and expression of nitrogen oxide synthase isoforms in corpus cavernosum of arteriogenic erectile dysfunction rat model. Zhonghua Yi Xue Za Zhi 2004; 84: 954–7. | PubMed | ChemPort |
10. Xin ZC, Kim EK, Lin CS, Liu WJ, Tian L, Yuan YM, et al. Effects of icariin on cGMP-specific PDE5 and cAMP-spe-cific PDE4 activities. Asian J Androl 2003; 5: 15–8. | PubMed | ChemPort |
11. Liu WJ, Xin ZC, Fu J, Xin H, Yuan YM, Tian L, et al. Effect of icariin on the mRNA and protein expression of NOS isform in corpus cavernosum of castrated rats. Chin Pharmacol Bull 2003: 19: 645–9. | ChemPort |
12. Palese MA, Crone JK, Burnett AL. A castrated mouse model of erectile dysfunction. J Androl 2003; 24: 699–703. | PubMed |
13. Traish AM, Park K, Dhir V, Kim NN, Moreland RB, Goldstein I. Effects of castration and androgen replacement on erectile function in a rabbit model. Endocrinology 1999; 140: 1861–8. | Article | PubMed | ISI | ChemPort |
14. Waterborg JH, Matthews HR. The Lowry method for protein quantitation. Methods Mol Biol 1994; 32: 1–4. | PubMed | ChemPort |
15. Baba K, Yajima M, Carrier S, Morgan DM, Nunes L, Lue TF, et al. Delayed testosterone replacement restores nitric oxide synthase-containing nerve fibers and the erectile response in rat penis. BJU Int 2000; 85: 953–8. | Article | PubMed | ISI | ChemPort |
16. Dai Q, Silverstein AD, Davies MG, Hagen PO, Donatucci CF, Annex BH. Systemic basic fibroblast growth factor induces favorable histological changes in the corpus cavernosum of hypercholesterolemic rabbits. J Urol 2003; 170: 664–8. | Article | PubMed | ChemPort |
17. Nathan C, Xie Q. Regulation of biosynthesis of nitric oxide. J Biol Chem 1994; 269: 13725–8. | PubMed | ISI | ChemPort |
18. Escrig A, Marin R, Mas M. Repeated PGE1 treatment enhances nitric oxide and erection responses to nerve stimulation in the rat penis by upregulating constitutive NOS isoforms. J Urol 1999; 162: 2205–10. | Article | PubMed | ISI | ChemPort |
19. Qiu F, Chen YJ, Kano YH, Yao XS. Metabolism of orally administered icariin in rats. Acta Pharm Sin 1999; 34: 222–6. | ChemPort |

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