Mechanical properties of the mammalian vas deferens. I. In the passive state.

Knowledge of the mechanical properties of the vas deferens is important in order to understand the mechanical interaction between an intravasal device (IVD) and the vas deferens—a necessary step for successful long-term implantation. It is equally important in order to understand the mechanism of sperm transport through the vas, with or without an IVD implant, by means of quantitative mechanical models. Experiments were performed, in vitro, on vas deferens from rat, bull, and rabbit, to determine its mechanical properties in the passive state. The data consist of (1) load response to simple extension and cyclic extension, (2) extensional response to cyclic loading, and (3) stress relaxation response at constant extensions. The load-elongation behavior is characterized by Fung's exponential model T = (T* + β)eα(λ-λ*) - β quantitatively, where T is the Lagrangian or engineering stress (current force in the specimen divided by the original area of cross section) (dyn/cm2), T* is a convenient stress value (dy...