Effects of mild diabetes on extracellular matrix and urethral striated muscle of pregnant ratsRESUMO DE TESE
Effects of mild diabetes on extracellular matrix and urethral striated muscle of pregnant rats
Efeito do diabete moderado na matriz extracelular e no músculo estriado uretral em ratas prenhes
Autora: Fernanda Piculo
Orientadora: Profa. Dra. Marilza Vieira Cunha Rudge
INTRODUCTION:Diabetes mellitus during pregnancy is associated with high levels of urinary incontinence and pelvic floor muscle dysfunction. Mild diabetes can lead to changes in urethral striated muscle and extracellular matrix in pregnant rats considering both structures as a whole system responsible for urinary continence.
METHODS: Ninety-two female Wistar rats were distributed in four experimental groups: virgin, pregnant, diabetic and diabetic pregnant. All experimental procedures were approved by the Ethics Committee on Animal Experiments of the Botucatu Medical School UNESP (Protocol Number 846). Mild diabetes was induced at the first day of birth by subcutaneous administration of streptozotocin at a dose of 100 mg/kg body weight. In adult life, parental non-diabetic female rats were mated with non-diabetic males to obtain newborns. On day 21 of the pregnancy, the rats were lethally anesthetized and the urethra and vagina were extracted as a unit. Urethral and vaginal sections were cut and analyzed by a) cytochemical staining for extracellular matrix and muscle components; b) immunohistochemistry to identify fast and slow muscle fibers; and c) transmission electron microscopy for ultrastructural analysis of urethral striated muscle.
RESULTS: In comparison to the three control groups, variations in the urethral striated muscle and extracellular matrix from diabetic pregnant rats were observed including: thinning, disorganization, atrophy, fibrosis, increased blood vessels, accumulation of subsarcolemmal and intermyofibrillar mitochondria, lipid droplets and glycogen granules associated with co-localization of fast and slow fibers and a steady decrease in the proportion of fast to slow fibers.
CONCLUSIONS: Mild diabetes and pregnancy can lead to time-dependent disorder and tissue remodeling in which the urethral striated muscle and extracellular matrix has a fundamental function.
Keywords: Diabetes; Extracellular matrix; Pregnancy; Rats; Urethral striated muscle
Palavras-chave: Diabetes; Matriz extracelular; Gravidez; Ratos; Musculo estriado
Dissertação de Mestrado apresentada ao Departamento de Ginecologia, Obstetrícia e Mastologia da Faculdade de Medicina de Botucatu-UNESP, em 22 de fevereiro de 2013.
Publication Dates
-
Publication in this collection
06 June 2013 -
Date of issue
Apr 2013
