*2.3. Histological Analysis*

After the thoracic aorta including PVAT had carefully been excised, the PVAT was isolated from the thoracic aorta and weighed. For staining hematoxylin and eosin (H&E) and trichrome, thoracic aorta and the surrounding thoracic PVAT (tPVAT) were fixed in 4% formalin overnight and then dehydrated and embedded in paraffin using conventional methods. Paraffin-embedded samples were sectioned to a thickness of 2.0 μm. After staining, slides were examined with light microscopy. We used ImageJ software (National Institutes of Health, Bethesda, MD, USA) to measure the area of the adipocytes. The calculated areas were multiplied by a conversion factor to determine the cross-sectional area of the adipocytes in μm2.
