Chronic sleep deprivation induces erectile dysfunction through increased oxidative stress, apoptosis, endothelial dysfunction, and corporal fibrosis in a rat model.

Abstract

Background: Sleep is foundational for nocturnal erections, facilitating nutrient exchange and waste removal, which has brought widespread attention to the relationship between sleep and erectile dysfunction (ED). However, there is currently a lack of basic research confirming whether chronic sleep deprivation (CSD) leads to erectile impairment and its underlying pathological mechanisms.

Aim: The study sought to investigate whether CSD impairs erectile function in rats and the potential tissue damage it may cause in rats.

Methods: The modified multiple platform method was employed to induce CSD in 14 rats, randomly divided into a platform control group and a CSD group. After 3 weeks, erectile function was evaluated by measuring intracavernosal pressure following cavernous nerve stimulation.

Outcomes: Arterial blood samples were then analyzed for testosterone levels, and cavernous tissues were processed for advanced molecular biology assays, including Western blotting and immunofluorescence.

Results: After inducing CSD, rats exhibited a marked reduction in erectile function, yet their serum testosterone levels remained statistically unchanged when compared with the control group. More importantly, rats in the CSD group exhibited a significant increase in oxidative stress levels, accompanied by low expression of HO-1 and high expression of NOX1 and NOX4. Subsequently, elevated oxidative stress induced increased apoptosis in smooth muscle and endothelial cells, as evidenced by significant decreases in CD31 and α-smooth muscle actin expression in the CSD group, demonstrated through Western blotting and immunofluorescence assays. Endothelial cell apoptosis led to a significant decrease in endothelial nitric oxide synthase, resulting in lowered levels of nitric oxide and cyclic guanosine monophosphate, which severely impaired the erectile mechanism. Additionally, activation of the transforming growth factor β1 fibrotic pathway led to increased levels of tissue fibrosis, resulting in irreversible damage to the penile tissue in the CSD group.

Clinical implications: Our study lacks further exploration of the molecular mechanisms linking CSD and ED, representing a future research focus for potential targeted therapies.

Strengths and limitations: Our findings demonstrated that CSD significantly impairs erectile function in rats.

Conclusion: CSD severely impairs erectile function in rats. When exposed to CSD, rats exhibit significantly elevated oxidative stress levels, which lead to increased tissue apoptosis, endothelial dysfunction, and ultimately irreversible fibrotic changes in the tissues. Further researches into the potential molecular mechanisms are needed to identify possible therapeutic targets for ED related to CSD.