Biochemical and ultrastructural changes in oral mucosa of riboflavin deficient rats

Abstract

Although cheilosis, angular stomatitis and glossitis are recognized as characteristic symptoms of ariboflavinosis, essential pathogenesis of the lesions is still unknown.In the present study, ultrastructural and biochemical changes of oral mucosa in rats fed on synthetic riboflavin deficient diet were examined.An enzymatic study of oral mucosa in riboflavin-depleted rats showed a decrease of succinate dehydrogenase and lactate dehydrogenase. No changes in LDH isoenzyme patterns of oral mucosa were found, but there was a significant decrease in LDH-5 of the skeletal muscle (masseter). The tongue in riboflvin deficient rats has a marked increase in lipid peroxide content.Scanning electron microscopy of angular mucosa in riboflavin deficient rats yielded a threedimentional view of densely arranged microplicae.Transmission electron microscopic observation of the same specimen revealed that the mitochodria became slightly enlarged in the basal layer and that tonofilaments and keratohyaline granules exihibited a decrease in number and concentration in the superficial layer.These results suggest that lipid peroxide raised in oral mucosa by riboflavin deficiency may play an important role in oral lesions.