An animal model to study lower urinary tract symptoms and erectile dysfunction: the hyperlipidaemic rat.
OBJECTIVE
To present evidence that rats fed a high-fat diet could serve as a useful animal model to study both lower urinary tract symptoms (LUTS) and erectile dysfunction (ED), as recent epidemiological studies have shown a strong association between LUTS and ED but the physiological basis behind this relationship is unknown.


METHODS
In all, 24 male Sprague-Dawley rats were divided into two groups: nine controls were fed a 'normal' diet and 15 were fed a high-fat diet (hyperlipidaemic rats). After 6 months all the rats had bladder and erectile functions evaluated using awake cystometry and cavernosal nerve electrostimulation, respectively. After the functional studies were completed, the penis, prostate and bladder were collected for immunohistochemical analysis.


RESULTS
The hyperlipidaemic rats had significantly higher serum cholesterol and low-density lipoprotein than the controls (P < 0.05). The hyperlipidaemic rats also had significantly worse erectile function (P = 0.004) and developed more bladder overactivity (P = 0.004) than the controls. In the hyperlipidaemic rats there was significant muscle hypertrophy in the peri-urethral lobe of the prostate (P < 0.001) and in the bladder (P < 0.05). There was also greater P2X(1) (purinoceptor) staining as well as other molecular changes in the bladder of the hyperlipidaemic rats.


CONCLUSIONS
In this hyperlipidaemic rat model three abnormalities were consistently detected: prostatic enlargement, bladder overactivity, and ED. This rat model could be a useful research tool for understanding the common causes of LUTS and ED, as well as facilitating the development of preventive measures and better therapies to treat both conditions.
Rahman
Nadeem U
NU
Knuppe Molecular Urology Laboratory, Department of Urology, University of California San Francisco School of Medicine, San Francisco, CA 94143-0788, USA.
Phonsombat
Surat
S
Bochinski
Derek
D
Carrion
Rafael E
RE
Nunes
Lora
L
Lue
Tom F
TF
D000818:Animals; D002784:Cholesterol / Q000097:blood; D004041:Dietary Fats / Q000009:adverse effects*; D004195:Disease Models, Animal; D007172:Erectile Dysfunction / Q000209:etiology* / Q000473:pathology; D006949:Hyperlipidemias / Q000150:complications / Q000473:pathology*; D007150:Immunohistochemistry; D008074:Lipoproteins / Q000097:blood; D008297:Male; D010413:Penis / Q000473:pathology; D011467:Prostate / Q000473:pathology; D053448:Prostatism / Q000209:etiology* / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D001743:Urinary Bladder / Q000473:pathology
D004041:Dietary Fats; D008074:Lipoproteins; D002784:Cholesterol