Functional hypertrophy and atrophy of the salivary glands of rats

Abstract

Feeding rats a diet with its caloric content reduced by addition of nonnutritive cellulose results in an increase in total food intake and in salivary gland weight. The increased gland weight is attributable to hypertrophy of the acinar cells. Prior parasympathectomy completely prevents the response. Sympathectomy has only a small effect. The bulk diet effect appears to be the result of an increased secretion of saliva secondary to ingesting excessive quantities of bulk diet. Reducing functional stimulation by feeding a liquid ration results in cessation of growth or atrophy of partoid glands, effects similar to those observed after complete autonomic denervation of these glands. For the submandibular glands, liquid diet retards gland growth; whereas denervation results in a true atrophy. The results support the idea that the level of functional demand is an important factor in regulating the growth rate of salivary glands. The innervation of the submandibular glands has a trophic action which is, in part, independent of functional stimulation.