BERKELEY, CA (UroToday.com) - Over the last few decades, there have been considerable advances made in our understanding of the pathophysiology and molecular basis of erectile dysfunction (ED).
While the complex nature of human sexual function cannot possibly be replicated fully, the use of animal models provides a valid alternative to the investigation and evaluation of sexual dysfunction. From the pioneering work by Eckhard (who, in 1863, demonstrated the importance of the pelvic nerves in erectile function), to the current researchers, animal experimentation has provided strong support in basic scientific concepts relating to sexual dysfunction and has increased our understanding of the pathophysiology of erectile dysfunction.
While larger animals such as dogs, monkeys, cats and rabbits were used in the early period of investigation (1960-1990), in recent times rodents have largely replaced other animals as the predominant animal model for investigating erectile function.
In this review article, we summarize the various animal models of ED and highlight the advantages and disadvantages of each model. The most frequently reported models of ED can be classified as traumatic (cavernous nerve injury and arterial ligation) and metabolic (diabetic, hypercholesterolemia/lipidemia and castration). Other models that have been studied include organic (smoking, hypertension and chronic renal failure) and non-organic (psychological) models as well as primary cell cultures of human penile tissue. Recent technological advances such as proteomic markers, cell-specific immunohistochemistry, and Western blot analyses have improved the functional and morphologic assessments of ED. In vitro studies using cavernosal tissues obtained from other animal models and human volunteers using primary cell cultures have assisted in defining the cellular mechanisms involved in erectile function, while in vivo experiments involving knock-out proteins and/or enzymes using various recombinant vectors and the use of cultured autologous cells such as mesenchymal stem cells have further advanced our pathophysiologic knowledge.
Continuous efforts are being made to exploit and evaluate the different types of animal models to best replicate disorders of sexual function. At present animal models play a significant role in evaluating novel therapeutics and surgical techniques and will likely continue to remain a vital research tool in the future.
Written by:
Eric Chung, FRACS as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.
Investigative models in erectile dysfunction: A state-of-the-art review of current animal models - Abstract
UroToday.com Erectile Dysfunction (ED) Section