Evaluation of erectile function in laboratory animals: an overview

Abstract 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.