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Updated: May 29, 2026
Cavernous Nerve Stimulation and Recording of Intracavernous Pressure in a Rat
Published on: April 23, 2018
Cavernous smooth muscle hyperplasia in a rat model of hyperlipidaemia-associated erectile dysfunction
Xuefeng Qiu1, Thomas M Fandel, Guiting Lin
1Knuppe Molecular Urology Laboratory, Department of Urology, University of California, San Francisco, USA.
Unlabelled:
What's known on the subject? and what does the study add? Increased cavernous smooth muscle content has been repeatedly observed in rat models of hyperlipidaemia - associated erectile dysfunction. This study shows that the increased smooth muscle content is due to hyperplasia.
Objective:
• To investigate the structural changes, including possible smooth muscle hyperplasia, in the penis of a hyperlipidaemia-associated erectile dysfunction (ED) animal model.
Materials And Methods:
• Hyperlipidaemia was induced in rats through a high-fat diet. • Penile tissues of normal and hyperlipidaemic rats were stained with Alexa-488-conjugated phalloidin and/or with antibodies against rat endothelial cell antigen, neuronal nitric oxide synthase (nNOS), and collagen type IV (Col-IV) before image and statistical analyses were carried out. • The main outcome measures were the smooth muscle, endothelial, Col-IV and nNOS content of the corpus cavernosum.
Results:
• Phalloidin intensely stained all smooth muscle in the penis, revealing the circular and longitudinal components of cavernous smooth muscle (CSM). • The CSM content was significantly higher in the hyperlipidaemic than in the normal rats (P < 0.05). • Cell numbers in both circular and longitudinal CSM were significantly higher in the hyperlipidaemic than in the normal rats (P < 0.05). • Cavernous endothelial content was significantly lower in hyperlipidaemic than in normal rats (P < 0.05). • nNOS-positive nerves within the dorsal nerves, around the dorsal arteries, and in the corpora cavernosa were all significantly lower in the hyperlipidaemic than in the normal rats (P < 0.05).
Conclusions:
• Hyperlipidaemia is associated with reduced nNOS-positive nerves, reduced endothelium, and increased CSM in the penis. • The increased CSM is attributable to hyperplasia. • These structural changes may explain why hyperlipidaemic men are more likely to develop ED.
