Anisotropias opticas em feixes de colageno e pesquisa de morte celular em fibroblastos de tendões durante o estabelecimento do diabetes espontaneo em camundongos não-obesos (NOD)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

NOD mice possess two characteristics: diabetes and resistance to various apoptosis signals. Diabetes mellitus provokes alterations in the extracellular matrix (ECM) through of the non-enzymatic glycosylation of intercellular proteins, such as the collagen. In the process of non-enzymatic glycosylation of the collagen protein, the carbonyl group of a sugar reacts with the amino group of a protein and forms a Schiffs? base which reacts further into a Amadori products. The products of early glycosylation undergo rearrangements resulting in the formation of irreversible products, the so-called advanced glycosylation endproducts (AGEs). AGEs formation is probably one of the main mechanisms underlying the increased arterial stiffness in diabetic patients or diabetic complications in general. The collagen interacts with cell receptors, consequently alterations in the collagen can change the signal transduction from ECM for the cells. The principal objectives of present study are: to describe the anisotropic properties of collagen bundles obtained from NOD mice and to compare some aspects of the cell death and nuclear phenotype of fibroblasts obtained from NOD and BALB/C mice. For this, calcaneal and tail tendons were submitted to the following experiments: measurements of intrinsical and textural birefringence; enzymatic digestion; staining with toluidine blue (TB) pH 4.0; Concanavalin Br method; collagen extraction; Feulgen reaction, analysis of nuclear images and TUNEL test. The results indicate that all glucose was converted the Amadori products. The increase in the number of cross-linking becomes the collagen fibers both more 16 aligned and with more intense molecular packing conditions than those of the control. In terms of molecular order (crystallinity) of collagen bundles, the diabetes induces variable changes in function of the structure, fact this that suggests the existence of different physio-pathogenics meanings. The analysis of parameters that characterize the nuclear phenotype (area, perimeter, OD, IOD, SDtd and entropy) indicate physiological differences between the fibroblasts obtained from NOD and BALB/C mice. The reply to the TUNEL test was negative in the fibroblasts

ASSUNTO(S)

fibroblasto colageno camundongo

ACESSO AO ARTIGO

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