Sural nerve involvement in experimental hypertension: morphology and morphometry in male and female normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR)

Autor(es)

Sanada, Luciana Sayuri ^[1] ; da Rocha Kalil, Andrea Lurdes ^[1] ; Tavares, Marcelo Rodrigo ^[1] ; Maia Neubern, Milena Cardoso ^{[1, 2]} ; Salgado, Helio Cesar ^[3] ; Sassoli Fazan, Valeria Paula ^{[1, 2]}

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Neurosci & Behav Neurosci, BR-14049900 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Dept Surg & Anat, BR-14049900 Sao Paulo - Brazil

^[3] Univ Sao Paulo, Sch Med Ribeirao Preto, Dept Physiol, BR-14049900 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: BMC NEUROSCIENCE; v. 13, MAR 2 2012.
• Citações Web of Science: 9

Resumo

Background: The sural nerve has been widely investigated in experimental models of neuropathies but information about its involvement in hypertension was not yet explored. The aim of the present study was to compare the morphological and morphometric aspects of different segments of the sural nerve in male and female spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats. Rats aged 20 weeks (N = 6 in each group) were investigated. After arterial pressure and heart rate recordings in anesthetized animals, right and left sural nerves were removed and prepared for epoxy resin embedding and light microscopy. Morphometric analysis was performed with the aid of computer software, and took into consideration the fascicle area and diameter, as well as myelinated fiber number, density, area and diameter. Results: Significant differences were observed for the myelinated fiber number and density, comparing different genders of WKY and SHR. Also, significant differences for the morphological (thickening of the endoneural blood vessel walls and lumen reduction) and morphometric (myelinated fibers diameter and G ratio) parameters of myelinated fibers were identified. Morphological exam of the myelinated fibers suggested the presence of a neuropathy due to hypertension in both SHR genders. Conclusions: These results indicate that hypertension altered important morphometric parameters related to nerve conduction of sural nerve in hypertensive animals. Moreover the comparison between males and females of WKY and SHR allows the conclusion that the morphological and morphometric parameters of sural nerve are not gender related. The morphometric approach confirmed the presence of neuropathy, mainly associated to the small myelinated fibers. In conclusion, the present study collected evidences that the high blood pressure in SHR is affecting the sural nerve myelinated fibers. (AU)

• Processo FAPESP: 06/03200-7 - Estudo morfológico e morfométrico do nervo sural de ratos normotensos, espontaneamente hipertensos (SHR) e espontaneamente hipertensos com diabete induzido experimentalmente
• Beneficiário: Valéria Paula Sassoli Fazan
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 04/09139-2 - Estudos morfofuncionais e morfométricos do sistema nervoso central e periférico e do sistema cardiovascular, envolvidos na regulação neuro-humoral de funções neurovegetativas e comportamentais
• Beneficiário: Helio Cesar Salgado
• Modalidade de apoio: Auxílio à Pesquisa - Programa Equipamentos Multiusuários
• Processo FAPESP: 10/12518-6 - Avaliação morfológica e comparação dos tipos de fibras dos músculos gastrocnêmios lateral e medial e flexor longo do hálux após estimulação dolorosa no período neonatal
• Beneficiário: Valéria Paula Sassoli Fazan
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 09/50389-6 - Regulação cardiocirculatória em condições fisiológicas e fisiopatológicas
• Beneficiário: Helio Cesar Salgado
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 09/16748-9 - Avaliação morfológica e morfométrica do nervo frênico de ratos espontaneamente hipertensos em diferentes fases do desenvolvimento
• Beneficiário: Valéria Paula Sassoli Fazan
• Modalidade de apoio: Auxílio à Pesquisa - Regular