Establishing a Thermal Imaging Technology (IRT) Based System for Evaluating Rat Erectile Function

Evaluation of erectile function in laboratory animals: an overview

INTRODUCTION

Erectile dysfunction (ED) is a common male sexual disorder that diminishes quality of life significantly. Despite extensive research, little is known about the complex physiological mechanisms of ED, in part owing to disparities between animal and human physiology. Comprehensive and objective assessment methods for animal models are crucial to bridge this translational gap.

OBJECTIVES

Various experimental approaches for evaluating erectile function in rodent models are explored.

METHODS

A search of the medical literature was carried out in PubMed and Medline, focusing on original research and systematic reviews of original research on the evaluation of erectile function in experimental animals. Studies without erectile assessment methods or insufficient data, editorials, letters, commentaries, and non-English articles were excluded.

RESULTS

The ICP-to-mean arterial pressure ratio remains a valuable indicator for evaluating erectile function. Furthermore, laser speckle blood perfusion imaging technology offers an approach for assessing changes in cavernous blood flow, whereas infrared thermal imaging technology enables real-time temperature monitoring during erectile responses. Microscopic ultrasound and magnetic resonance imaging allow high-resolution observation of hemodynamic and histological changes in the rat model penis, real-time assessment of blood flow, and detailed anatomical information. Human-rat homologous marker detection using blood tests has high clinical relevance and translational potential. In addition, wearable adaptive penile rigidity monitoring (WARM) dynamically monitors erectile function by accurately and continuously detecting changes in the girth of the rat penis in a non-invasive manner. Utilizing ex vivo models of cavernous tissue, such as the cavernous artery and smooth muscle, can provide valuable insights into the mechanisms underlying ED and the pharmacological effects and efficacy of drugs.

CONCLUSION

This comprehensive review covers diverse approaches, including new technologies, for assessing erectile function in rodent models, including new technologies. By addressing the limitations of the existing methodologies and providing a framework for accurate and reliable evaluations, this review provides a basis for further research on the pathophysiology of ED and potential therapeutic interventions.

Therapeutic potential of salidroside in type I diabetic erectile dysfunction: Attenuation of oxidative stress and apoptosis via the Nrf2/HO-1 pathway

The primary objective of this work was to delve into the potential therapeutic advantages and dissect the molecular mechanisms of salidroside in enhancing erectile function in rats afflicted with diabetic microvascular erectile dysfunction (DMED), addressing both the whole-animal and cellular dimensions.We established a DMED model in Sprague‒Dawley (SD) rats and conducted in vivo experiments. The DMED rats were administered varying doses of salidroside, the effects of which on DMED were compared. Erectile function was evaluated by applying electrical stimulation to the cavernous nerves and measuring intracavernous pressure in real time. The penile tissue underwent histological examination and Western blotting. Hydrogen peroxide (H2O2) was employed in the in vitro trial to induce an oxidative stress for the purpose of identifying alterations in cell viability. The CCK-8 assay was used to measure the viability of corpus cavernous smooth muscle cells (CCSMCs) treated with vs. without salidroside. Flow cytometry was utilized to detect alterations in intracellular reactive oxygen species (ROS). Apoptosis was assessed through Western blotting and TdT-mediated dUTP nick-end labelling (TUNEL). Animal and cellular experiments indicate that the Nrf2/HO-1 signalling pathway may be upregulated by salidroside, leading to the improvement of erectile function in diabetic male rats by alleviating oxidative stress and reducing apoptosis in corpus cavernosum tissue.

Galectin-3 is involved in inflammation and fibrosis in arteriogenic erectile dysfunction via the TLR4/MyD88/NF-κB pathway

Galectin-3 (Gal-3) is a multifunctional protein that has been linked to fibrosis and inflammation in the cardiovascular system. In this study, we examined the impact of Gal-3 on inflammation and fibrosis in patients with arteriogenic erectile dysfunction (A-ED) and the underlying mechanisms involved. To induce arterial injury, we utilized cuffs on the periaqueductal common iliac arteries of Sprague‒Dawley (SD) rats and administered a high-fat diet to co-induce local atherosclerosis. Our results showed that we successfully developed a novel A-ED model that was validated based on histological evidence. In vivo, the vascular lumen of rats subjected to a high-fat diet and cuff placement exhibited significant narrowing, accompanied by the upregulation of Gal-3, Toll-like receptor 4 (TLR4), and myeloid differentiation primary response protein 88 (MyD88) expression in the penile cavernosa. This led to the activation of nuclear factor kappa B 65 (NF-κB-p65), resulting in reduced intracavernosal pressure, endothelial nitric oxide synthase expression, and smooth muscle content, promoting inflammation and fibrosis. However, treatment with Gal-3 inhibitor-modified citrus pectin (MCP) significantly normalized those effects. In vitro, knocking down Gal-3 led to a significant reduction in TLR4, MyD88, and NF-κB-p65 expression in corpus cavernosum smooth muscle cells (CCSMCs), decreasing inflammation levels. In conclusion, inhibiting Gal-3 may improve A-ED by reducing inflammation, endothelial injury, and fibrosis in the penile corpus cavernosum through the TLR4/MyD88/NF-κB pathway. These findings highlight the potential therapeutic target of Gal-3 in A-ED.