부산대학교 도서관

Previously it was assumed that nerve fibres are involved in the neurogenicinflammation induced by mechanical or chemical irriations. It has been alsosuggested that in diabetes mellitus the unmyelinated small diameter fibersare impaired as a result of diabetic neuropathy. Therefore, our aim was tostudy the alterations of the nerve processes in the gingivomucosal tissuein streptozotocin (STZ)-diabetic rats. Light- and electronmicroscopical examinationswere made to analyze the changes in nerve fibres. After one week of steptozotocintreatment, the gingivomucosal tissue had inflammatory cell infiltration andsome degenerated nerve fibres were also observed. Dense mitochondria, disorganizationof cell organelles, and appearance of myelin-like dense bodies were foundin the axons of degenerared nerve fibres. Semiquantitative analysis showedthat 14 ± 4% of the unmyelinated nerve fibres degenerated after oneweek of STZ treatment. However, degeneration of the myelinated nerve fiberswas not observed. Two weeks after STZ treatment, most of the unmyelinatedand myelinated nerve fibers showed degeneration (86 ± 5%) and the placementof the ligature revealed a non-inflammatory connective tissue adjacent toa normal epithelium. The myelin sheath was disrupted and dark axoplasm withcytolysosomes became manifest. These findings demonstrated that both unmyelinatedand myelinated nerve fibers are altered and inflammatory reaction exists inthe gingivomucosal tissue only in the early stage of diabetes mellitus. [ABSTRACT FROM AUTHOR]