Infection of the Accessory Sinuses and Upper Respiratory Tract in Avitaminosis of Rats

Abstract

Wolbach and Howe 1 found a metaplasia of the epithelial membrane in rats suffering from lack of vitamins A and D. Goldblatt and Benischek,2 as well as Green and Mellanby,3 reported similar changes following feeding of rats on diets deficient only in vitamin A. Daniels 4 and we 5 definitely showed that animals (albino rats), when placed on diets lacking fat-soluble vitamin A, develop pyogenic infections in the sinuses and nasal cavities. Lawson 6 stated that the epithelial membrane lining the normal sinus, for practical purposes, is histologically similar to that found in the various nasal cavities and the upper respiratory portion of the nose. He distinguished it from the membrane of the general respiratory tract by its thinness and scarcity of glandular tissue. This thinness, he remarked, is more pronounced in the region of the ethmoid cells. Characteristic of this membrane in normal conditions is a mucous secretion covering it, which offers resistance to bacterial invasion. Why is it that purulent suppurations develop particularly in the ethmoidal region of the nasal cavities in animals deprived of vitamin A? The flora of the upper respiratory tract of the control and of the stock animal may show organisms similar to those found in the suppurations of the xerophthalmic animal. An average of 54 per cent of seventy-three animals receiving an adequate supply of vitamin A showed positive cultures from the nasal cavities, but suppuration was absent in 100 per cent. Purulent suppurations were