Salivary glands as endocrine organs

Abstract
Total bilateral extirpation of submaxillary and sublingual glands produced in five dogs a significant increase of insulin sensitivity as measured by insulin sensitivity test. The glucose tolerance test in the same animals showed a less significant and less constant increase of the utilization of the administered glucose. Similar results were obtained in four dogs with a complete bilateral ligation of the secretory ducts, which resulted in the atrophy of the submaxillary and sublingual glands. Fourteen control experiments failed to show any significant fluctuations in insulin sensitivity or in utilization of the administered glucose. It is concluded that submaxillary and, possibly, sublingual glands are producing a factor which, if removed, potentiates the action of insulin; this factor is designated as submaxillary insulin inhibitor (S.I.I.). Submaxillary glands in dogs possess argentaffine cells in a large amount, and they are identified as the demilune formations; these cells have histochemical characteristics similar to the argentaffine cells found in the gastrointestinal tract. Note: (With the Technical Assistance of E. J. Kaminski) Submitted on January 29, 1959