Transmission Electron Microscopy Studies of the Vestibulocochlear Nerve in Chronic Diabetic Rats

Autor(es)

Carvalho de Vasconcelos, Carlos Augusto ^{[1, 2]} ; Sassoli Fazan, Valeria Paula ^[3] ; Moore, Kenneth Charles ^[4] ; Nessler, Randy Alan ^[4] ; Valenca, Marcelo Moraes ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Pernambuco, Dept Neuropsychiat, Div Neurol & Neurosurg, Recife, PE - Brazil

^[2] Lab Immunopathol Keizo Asami LIKA, Elect Microscopy Sect, Recife, PE - Brazil

^[3] USP, Sch Med Ribeirao Preto, Dept Neurosci & Behav Neurosci, BR-14049900 Ribeirao Preto, SP - Brazil

^[4] Univ Iowa, Cent Microscopy Res Facil, Iowa City, IA - USA

• Tipo de documento: Artigo Científico
• Fonte: INTERNATIONAL JOURNAL OF MORPHOLOGY; v. 29, n. 1, p. 272-277, MAR 2011.
• Citações Web of Science: 2

Resumo

It is widely described in the literature that diabetic patients present hearing impairment. Despite the histological alterations of the internal ear structures in these patients as well as in experimental models of diabetes, to the best of our knowledge, an histological evaluation of the vestibulocochlear nerve have not been performed. In the present study, ultrastructural alterations are described and compared between a spinal nerves and a cranial nerve in rats with chronic induced diabetes. Male Wistar rats (n = 12), fed with standard diet from the animal care facility at 42 days of age were used. Induced diabetic animals (n = 6) were fasted for 12 hours prior to being injected intraperitoneally with streptozotocin (STZ - 60mg/kg) in a single dose. Control animals (n = 6) received (0.01 mol/l citrate buffer, pH 4.5) vehicle alone. Ten weeks after STZ injection the animals were perfused intracardially with Karnovsky solution. Right and left vestibulocochlear nerves were dissected and histologically processed for epoxy resin embedding. Samples were imaged with the transmission electron microscope. Large myelinated fibers with morphological signs of axonal atrophy in the vestibulocochlear nerves were readily observed. These results suggest that chronic STZ-induced diabetes in rats caused alterations in the myelinated fibers and Schwann cells, compatible to the classic diabetes signs and symptoms. Morphological alterations of the vestibulocochlear nerve in diabetes is described for the first time and contributes information for a better understanding of why there are changes in hearing observed in diabetic patients. (AU)

• Processo FAPESP: 06/06362-8 - Avaliação morfológica ultraestrutural das alterações do nervo renal de ratos diabéticos induzidos experimentalmente
• Beneficiário: Valéria Paula Sassoli Fazan
• Modalidade de apoio: Bolsas no Exterior - Pesquisa
• Processo FAPESP: 09/50389-6 - Regulação cardiocirculatória em condições fisiológicas e fisiopatológicas
• Beneficiário: Helio Cesar Salgado
• Modalidade de apoio: Auxílio à Pesquisa - Temático