Stimulus Specific Response on Mechanical Properties of Isolated Visceral Muscle Tissues of a Reptile, Uromastix hardwickii

ABSTRACT Mechanical properties of a muscle have traditionally been described on the basis of the characteristics of parallel elastic component(PEC), series elastic component(SEC) and contractile element(CE). Reptiles in general and Uromastix in particular have been less investigated regarding the mechanical responses and the characteristics of elastic elements of their visceral muscle tissues. Therefore, a comparative study was conducted to determine the mechanical properties of esophageal and intestine tissue strips of Uromastix hardwickii. Tissues were subjected to electrical stimulation in order to observe the graded mechanical response, and the quick isotonic release method was used for the measurement of stiffness in the series elastic component. The higher stiffness in intestinal tissues as compared to esophageal tissue of Uromastix is probably associated with its lesser compliance due to a lesser quantity of SEC that makes the intestine stiffer, as its muscle cells are less embedded in a collagen matrix. A significant difference between both types of muscle strips was observed in the rate of force re-development and change in their length. Thus, the present study provokes the need for quantitative histological and histo-chemical studies on the non-contractile proteins of Uromastix smooth muscle.