An animal model to study lower urinary tract symptoms and erectile dysfunction: the hyperlipidaemic rat

Abstract

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. MATERIALS AND 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 P2X1 (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.

Body mass index and risk of BPH: a meta-analysis

“…In an animal model, rats fed a high-fat diet, leading to hyperlipidemia, are found to develop prostatic enlargement and bladder overactivity. 48 Obesity has been hypothesized to be associated with BPH because of the endocrine changes in men that occur with age. Abdominal obesity increases the estrogen to androgen ratio and may increase sympathetic nervous activity, both known to influence the development of BPH and the severity of urinary obstructive symptoms.…”

Metabolic syndrome and BPH: What do we know?

“…This association was first established in rats in the year 2007 by Rahman et al where they reported a significantly higher prostatic weight in hyperlipidemic rats (2.6 vs 1.4 g; p < 0.01). 4 Subsequently, this fact has been strengthened in human studies also. Hammarsten et al reported a mean prostate volume of 49 ml vs 39 ml in patients with low serum HDL levels as compared to those with normal serum levels.…”

Lard and/or canola oil-rich diets induce penile morphological alterations in a rat model

“…Western pattern diet has been used in rodent models to investigate the biochemical characteristics and erectile function 5,7 .…”

“…It is known that unhealthy diets (rich in cholesterol, for example) are associated with inflammation and the presence of cellular adhesion molecules, which causes injury to the endothelial cells by oxidative stress 5 . On the other hand, the replacement of saturated fatty acid (SFA) with polyunsaturated fatty acid (PUFA) seems to be a great alternative in the prevention of metabolic diseases and endothelial dysfunction 6 , which could diminish the risk of development of ED.…”