Mechanical properties of semicircular canals in fish, frog and guinea pig

Abstract

A tension test was performed on the semicircular canals of fish, frogs and guinea pigs, with a tension testing machine capable of measuring microloads (the "microtension tester"). The mechanical properties of the semicircular canals were examined.
The semicircular canals of guinea pigs were so fine that no exact data could be obtained. The elongation, elastic modulus and tensile strength of fresh semicircular canals was 115.9%, 2.23 kgf/mm² and 0.88 kgf/ mm², respectively, in fish and 83.7%, 1.25 kgf/mm² and 0.46 kgf/mm², respectively, in frogs.
The thickness of the semicircular canals was compared. The frog's semicircular canals were the thickest, followed by those of fish, and the guinea pig's were the thinnest. The comparison of strength considering membranous thickness of the semicircular canals was performed. The frog's semicircular canals were the strongest, followed by those of fish, and the guinea pig's were the weakest. There was a good correlation between the thickness and the strength of the semicircular canals.
These findings suggest that the increase of the endolymph volume takes place throughout the entire labyrinth in Meniere's disease, and because of the thick membranes of the semicircular canals and the utricle, endolympatic hydrops is seen only in the cochlea and the saccule.