Castration Causes Progressive Reduction of Length of the Rabbit Penis

Androgenic hormones are important in normal embryonic development and maintenance of the structural integrity of the penis. This structural integrity is vital in the physiology of penile erection. Its alteration may therefore lead to functional impairment resulting in erectile dysfunction as seen in hypogonadic conditions. The link between hypogonadism and erectile dysfunction is partly anatomical, involving alteration of normal structural elements of the penis such as smooth muscle cells, connective tissue fibers and vascular sinusoids. The penile length, although considered controversial issue, may also be influenced by such tissue alterations. Understanding of the alterations of the penile size in hypogonadism is important in clinical examination of hypogonadic patients. The aim of this study was to describe the changes in the rabbit penile length after castration. Fifteen adult male rabbits were used for the study. Nine of these were castrated under local anesthesia to induce hypogonadism and six remained as controls. The penile lengths were measured using a digital Vernier caliper (accuracy 0.5mm). There was progressive reduction in the average non-erect penile length by 0.7%, 3.4% and 8.7% in the castrated group at the end of the third, sixth and ninth week respectively. Castration causes progressive reduction in the non-erect penile length. Such length reduction may impair the normal penile physiology hence contribute to anatomical basis of erectile dysfunction in hypogonadism.