Mucopolysaccharides in the Oral Mucosa of the Thyroidectomized Rat

¹ Loyola University School of Dentistry, Chicago, Illinois

An experiment to study the possible alterations of the connective tissue in the oral mucosa of thyroidectomized rats was performed. Special attention was given to the study of the mucopolysaccharide components of the ground substance of the connective tissue. A comparative evaluation of the oral mucosa from TX and normal animals was done.

Thirteen male albino rats were used. Nine of these animals were thyro-parathyroidectomized at the age of 4 weeks, while the remaining 4 animals were used as controls. The animals were sacrificed at the age of 7 months. Tissue specimens were obtained from the oral lining and masticatory mucosa and skin. The tissues were treated by either the freeze-drying method or alcohol-acetic acid and acridine-ethanol fixative solutions. Different histochemical stainings for the determination of mucopolysaccharides were used: toluidine blue, thionin, and PAS. Also, the following histologic methods were used to study the fiber components and general morphology of the connective tissue: Gomori silver impregnation, Heidenhain's azan stain, and hematoxylin and eosin. Enzyme incubation in testicular hyaluronidase and amylase was also done.

The results led us to the following conclusions: Thyroidectomy caused alterations in the connective tissue of the oral mucosa of the rat similar to those that have been previously described in skin—this alteration was in the form of a moderate increase in acid mucopolysaccharides, especially hyaluronic acid, in the ground substance of the connective tissue of TX rats. The oral tissues did not present any clinically visible sign of "myxedema." There was a greater content of amylase-removable glycogen in the mast cells of TX animals than in normal animals.