Effects of icariin on erectile function and expression of nitric oxide synthase isoforms in castrated rats.
OBJECTIVE
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/[kg.day] for group C and 5 mg/[kg.day] 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.


CONCLUSIONS
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.
Liu
Wu-Jiang
WJ
Andrology Center of Peking University First Hospital, Beijing 100009, China.
Xin
Zhong-Cheng
ZC
Xin
Hua
H
Yuan
Yi-Ming
YM
Tian
Long
L
Guo
Ying-Lu
YL
D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001794:Blood Pressure; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D007172:Erectile Dysfunction / Q000188:drug therapy* / Q000378:metabolism; D005419:Flavonoids / Q000494:pharmacology*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D008297:Male; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology; D019001:Nitric Oxide Synthase / Q000235:genetics* / Q000378:metabolism; D052248:Nitric Oxide Synthase Type I / Q000235:genetics / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000235:genetics / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000235:genetics / Q000378:metabolism; D009919:Orchiectomy; D010410:Penile Erection / Q000187:drug effects*; D010413:Penis / Q000187:drug effects / Q000201:enzymology; D011312:Pressure; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D013739:Testosterone / Q000097:blood
D004365:Drugs, Chinese Herbal; D005419:Flavonoids; D012333:RNA, Messenger; D013739:Testosterone; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; C496318:Nos2 protein, rat; D015106:3',5'-Cyclic-GMP Phosphodiesterases; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5; C517384:Pde5a protein, rat; C056599:icariin