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Updated: Jul 21, 2025
Intracavernous Pressure Recording in a Cavernous Nerve Injury Rat Model
Published on: September 20, 2021
Effect of hypoandrogenism on expression of transient receptor potential vanilloid channels in rat penile corpus
Gang Liu1, Jing Liu1, Xiangjun Kong1
1Department of Urology, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, China.
Background:
Hypoandrogenism is a cause of erectile dysfunction (ED). Vascular smooth muscle cell contraction and relaxation are regulated by TRPV1-4 channels. However, the influence of hypoandrogenism on TRPV1-4 and its relationship with erectile function remain unclear.
Aim:
To reveal whether hypoandrogenism affects erectile function by influencing TRPV1-4 expression in the corpus cavernosum of rats.
Methods:
Male Sprague-Dawley rats (N = 36) aged 8 weeks were assigned to 6 groups at random (n = 6): sham operation, castrated, castrated + testosterone replacement, sham operation + transfection, castrated + transfection, and castrated + empty transfection. Four weeks after castration, 20 μL of lentiviral vector (1 × 108 TU/mL) carrying the TRPV4 gene was injected into the penile cavernous tissue of the transfection groups. One week after transfection, the maximum intracavernous pressure (ICPmax)/mean arterial pressure (MAP) and the content of TRPV1-4, phosphorylated eNOS (p-eNOS)/eNOS, and nitric oxide (NO) in penile cavernous tissue of each group were measured.
Outcomes:
Under low androgen conditions, TRPV4 expression in endothelial cells in the rat penile cavernosum was sharply reduced, resulting in a decrease in p-eNOS/eNOS and NO content, which could inhibit erectile function.
Results:
In rat penile cavernous tissue, TRPV1-4 was expressed in the cell membranes of endothelial cells and smooth muscle cells. The ICPmax/MAP and the content of TRPV4, p-eNOS/eNOS, and NO end product nitrite level in rat penile cavernous tissue was markedly reduced in the castrated group as compared with the sham group (P < .05). The ICPmax/MAP and the content of TRPV4, p-eNOS/eNOS, and NO end product nitrite level in rat penile cavernous tissue were markedly improved in the castrated + transfection group vs the castrated group (P < .01).
Clinical Implications:
Upregulation of TRPV4 expression in penile cavernosum tissue might be a viable therapeutic for ED caused by hypoandrogenism.
Strengths And Limitations:
The specific mechanism of TRPV4 in ED needs to be further verified by androgen receptor or TRPV4 gene knockout experiments.
Conclusion:
Hypoandrogenism may cause ED by reducing the expression of TRPV4 in rat penile cavernous tissue. Upregulation of TRPV4 expression in penile cavernous tissue can increase the ratio of p-eNOS/eNOS and NO levels and ameliorate the erectile function of castrated rats.
