Modeling the contractile characteristics of smooth muscle from the porcine small intestine

Abstract

Defining the physiological condition of smooth muscle in more detail is the key to understanding the disease mechanism of smooth muscle defective diseases and the development of novel medical devices to help patients with these diseases. Although previous studies have detailed the physiological condition of smooth muscle contraction in gastrointestinal tracts, the precise characteristics of muscle contraction before or after stimulation have yet to be determined due to a lack of accuracy or inconsistency. Here, we obtain the passive characteristic parameters of smooth muscle and the active characteristic parameters of smooth muscle contraction from the porcine small intestine. To obtain the passive characteristic parameters of smooth muscle, we measured tensile strength in the porcine small intestine. The maximum repulsive force, 0.702 N, was measured in tensile tests. To estimate the active characteristic parameters of smooth muscle, we stimulated with acetylcholine and measured the isometric and isotonic contractions in the porcine small intestine. The maximum myotility, 12.35 mN, was obtained in isometric experiments, and the maximum velocity of muscular contraction, 0.4476 mm/min, was obtained in isotonic experiments. By applying the data acquired through experiments to the modified Hill-type muscle model, the active and passive characteristics of the porcine small intestine were schematized. Our model of smooth muscle from the porcine small intestine may be helpful for developing novel medical devices and understanding the physiology of smooth muscle in the porcine small intestine.