The use of quantitative and qualitative approach to evaluate fat distribution and morphology in white adipose tissue

Introduction: White adipose tissue (WAT) is the main responsible for the development of obesity and a diverse number of morphological techniques can be applied in its studies. Material and Methods: The present work was approved by an Ethics Committee (CEUA-827). Male C57BL/6 mice (12-wk-old) were fed a standard chow (CON) or high-fat diet (FAT) for 12 weeks. Body mass (BM) was assessed at the beginning and end of experiment period. After sacrifice and tissue extraction, fat distribution and adiposity index were measured. Plasmatic analyses were performed for cholesterol and triacylglycerol. Formalin-fixed epididymal adipose tissue was prepared for morphometric estimation of adipocytes diameter and stereological estimation of adipocytes density and cross-sectional area. Results: FAT group presented increased final BM, cholesterol, triacylglycerol and adiposity index when compared to CON group. Fat distribution revealed an increased amount of retroperitoneal, epididymal and inguinal fat pads in FAT in comparison to CON group. Qualitative histological analyses showed crown-like structures in FAT group. Morphometric and stereological analyses revealed adipocytes hypertrophy with increased diameter and sectional area in FAT group when compared to CON. FAT group also presented decreased numerical density of adipocytes in comparison to CON. Conclusion: The methods used to analyze WAT in this study act as important tools to elucidate morphological differences in this tissue induced by high fat diet in an obesity model.